diff options
Diffstat (limited to 'Documentation')
26 files changed, 1203 insertions, 270 deletions
diff --git a/Documentation/HOWTO b/Documentation/HOWTO index 6c9e746267da..915ae8c986c6 100644 --- a/Documentation/HOWTO +++ b/Documentation/HOWTO @@ -603,7 +603,8 @@ start exactly where you are now. ---------- -Thanks to Paolo Ciarrocchi who allowed the "Development Process" section +Thanks to Paolo Ciarrocchi who allowed the "Development Process" +(http://linux.tar.bz/articles/2.6-development_process) section to be based on text he had written, and to Randy Dunlap and Gerrit Huizenga for some of the list of things you should and should not say. Also thanks to Pat Mochel, Hanna Linder, Randy Dunlap, Kay Sievers, diff --git a/Documentation/arm/Sharp-LH/ADC-LH7-Touchscreen b/Documentation/arm/Sharp-LH/ADC-LH7-Touchscreen new file mode 100644 index 000000000000..1e6a23fdf2fc --- /dev/null +++ b/Documentation/arm/Sharp-LH/ADC-LH7-Touchscreen @@ -0,0 +1,61 @@ +README on the ADC/Touchscreen Controller +======================================== + +The LH79524 and LH7A404 include a built-in Analog to Digital +controller (ADC) that is used to process input from a touchscreen. +The driver only implements a four-wire touch panel protocol. + +The touchscreen driver is maintenance free except for the pen-down or +touch threshold. Some resistive displays and board combinations may +require tuning of this threshold. The driver exposes some of it's +internal state in the sys filesystem. If the kernel is configured +with it, CONFIG_SYSFS, and sysfs is mounted at /sys, there will be a +directory + + /sys/devices/platform/adc-lh7.0 + +containing these files. + + -r--r--r-- 1 root root 4096 Jan 1 00:00 samples + -rw-r--r-- 1 root root 4096 Jan 1 00:00 threshold + -r--r--r-- 1 root root 4096 Jan 1 00:00 threshold_range + +The threshold is the current touch threshold. It defaults to 750 on +most targets. + + # cat threshold + 750 + +The threshold_range contains the range of valid values for the +threshold. Values outside of this range will be silently ignored. + + # cat threshold_range + 0 1023 + +To change the threshold, write a value to the threshold file. + + # echo 500 > threshold + # cat threshold + 500 + +The samples file contains the most recently sampled values from the +ADC. There are 12. Below are typical of the last sampled values when +the pen has been released. The first two and last two samples are for +detecting whether or not the pen is down. The third through sixth are +X coordinate samples. The seventh through tenth are Y coordinate +samples. + + # cat samples + 1023 1023 0 0 0 0 530 529 530 529 1023 1023 + +To determine a reasonable threshold, press on the touch panel with an +appropriate stylus and read the values from samples. + + # cat samples + 1023 676 92 103 101 102 855 919 922 922 1023 679 + +The first and eleventh samples are discarded. Thus, the important +values are the second and twelfth which are used to determine if the +pen is down. When both are below the threshold, the driver registers +that the pen is down. When either is above the threshold, it +registers then pen is up. diff --git a/Documentation/arm/Sharp-LH/LCDPanels b/Documentation/arm/Sharp-LH/LCDPanels new file mode 100644 index 000000000000..fb1b21c2f2f4 --- /dev/null +++ b/Documentation/arm/Sharp-LH/LCDPanels @@ -0,0 +1,59 @@ +README on the LCD Panels +======================== + +Configuration options for several LCD panels, available from Logic PD, +are included in the kernel source. This README will help you +understand the configuration data and give you some guidance for +adding support for other panels if you wish. + + +lcd-panels.h +------------ + +There is no way, at present, to detect which panel is attached to the +system at runtime. Thus the kernel configuration is static. The file +arch/arm/mach-ld7a40x/lcd-panels.h (or similar) defines all of the +panel specific parameters. + +It should be possible for this data to be shared among several device +families. The current layout may be insufficiently general, but it is +amenable to improvement. + + +PIXEL_CLOCK +----------- + +The panel data sheets will give a range of acceptable pixel clocks. +The fundamental LCDCLK input frequency is divided down by a PCD +constant in field '.tim2'. It may happen that it is impossible to set +the pixel clock within this range. A clock which is too slow will +tend to flicker. For the highest quality image, set the clock as high +as possible. + + +MARGINS +------- + +These values may be difficult to glean from the panel data sheet. In +the case of the Sharp panels, the upper margin is explicitly called +out as a specific number of lines from the top of the frame. The +other values may not matter as much as the panels tend to +automatically center the image. + + +Sync Sense +---------- + +The sense of the hsync and vsync pulses may be called out in the data +sheet. On one panel, the sense of these pulses determine the height +of the visible region on the panel. Most of the Sharp panels use +negative sense sync pulses set by the TIM2_IHS and TIM2_IVS bits in +'.tim2'. + + +Pel Layout +---------- + +The Sharp color TFT panels are all configured for 16 bit direct color +modes. The amba-lcd driver sets the pel mode to 565 for 5 bits of +each red and blue and 6 bits of green. diff --git a/Documentation/devices.txt b/Documentation/devices.txt index 3c406acd4dfa..b369a8c46a73 100644 --- a/Documentation/devices.txt +++ b/Documentation/devices.txt @@ -1721,11 +1721,6 @@ Your cooperation is appreciated. These devices support the same API as the generic SCSI devices. - 97 block Packet writing for CD/DVD devices - 0 = /dev/pktcdvd0 First packet-writing module - 1 = /dev/pktcdvd1 Second packet-writing module - ... - 98 char Control and Measurement Device (comedi) 0 = /dev/comedi0 First comedi device 1 = /dev/comedi1 Second comedi device diff --git a/Documentation/dvb/get_dvb_firmware b/Documentation/dvb/get_dvb_firmware index 15fc8fbef67e..4820366b6ae8 100644 --- a/Documentation/dvb/get_dvb_firmware +++ b/Documentation/dvb/get_dvb_firmware @@ -259,9 +259,9 @@ sub dibusb { } sub nxt2002 { - my $sourcefile = "Broadband4PC_4_2_11.zip"; + my $sourcefile = "Technisat_DVB-PC_4_4_COMPACT.zip"; my $url = "http://www.bbti.us/download/windows/$sourcefile"; - my $hash = "c6d2ea47a8f456d887ada0cfb718ff2a"; + my $hash = "476befae8c7c1bb9648954060b1eec1f"; my $outfile = "dvb-fe-nxt2002.fw"; my $tmpdir = tempdir(DIR => "/tmp", CLEANUP => 1); @@ -269,8 +269,8 @@ sub nxt2002 { wgetfile($sourcefile, $url); unzip($sourcefile, $tmpdir); - verify("$tmpdir/SkyNETU.sys", $hash); - extract("$tmpdir/SkyNETU.sys", 375832, 5908, $outfile); + verify("$tmpdir/SkyNET.sys", $hash); + extract("$tmpdir/SkyNET.sys", 331624, 5908, $outfile); $outfile; } diff --git a/Documentation/feature-removal-schedule.txt b/Documentation/feature-removal-schedule.txt index 421bcfff6ad2..f50cf8fac3f0 100644 --- a/Documentation/feature-removal-schedule.txt +++ b/Documentation/feature-removal-schedule.txt @@ -57,6 +57,15 @@ Who: Jody McIntyre <scjody@steamballoon.com> --------------------------- +What: sbp2: module parameter "force_inquiry_hack" +When: July 2006 +Why: Superceded by parameter "workarounds". Both parameters are meant to be + used ad-hoc and for single devices only, i.e. not in modprobe.conf, + therefore the impact of this feature replacement should be low. +Who: Stefan Richter <stefanr@s5r6.in-berlin.de> + +--------------------------- + What: Video4Linux API 1 ioctls and video_decoder.h from Video devices. When: July 2006 Why: V4L1 AP1 was replaced by V4L2 API. during migration from 2.4 to 2.6 @@ -203,15 +212,6 @@ Who: Greg Kroah-Hartman <gregkh@suse.de> --------------------------- -What: Support for NEC DDB5074 and DDB5476 evaluation boards. -When: June 2006 -Why: Board specific code doesn't build anymore since ~2.6.0 and no - users have complained indicating there is no more need for these - boards. This should really be considered a last call. -Who: Ralf Baechle <ralf@linux-mips.org> - ---------------------------- - What: USB driver API moves to EXPORT_SYMBOL_GPL When: Febuary 2008 Files: include/linux/usb.h, drivers/usb/core/driver.c diff --git a/Documentation/filesystems/sysfs.txt b/Documentation/filesystems/sysfs.txt index c8bce82ddcac..89b1d196ca80 100644 --- a/Documentation/filesystems/sysfs.txt +++ b/Documentation/filesystems/sysfs.txt @@ -246,6 +246,7 @@ class/ devices/ firmware/ net/ +fs/ devices/ contains a filesystem representation of the device tree. It maps directly to the internal kernel device tree, which is a hierarchy of @@ -264,6 +265,10 @@ drivers/ contains a directory for each device driver that is loaded for devices on that particular bus (this assumes that drivers do not span multiple bus types). +fs/ contains a directory for some filesystems. Currently each +filesystem wanting to export attributes must create its own hierarchy +below fs/ (see ./fuse.txt for an example). + More information can driver-model specific features can be found in Documentation/driver-model/. diff --git a/Documentation/firmware_class/README b/Documentation/firmware_class/README index 43e836c07ae8..e9cc8bb26f7d 100644 --- a/Documentation/firmware_class/README +++ b/Documentation/firmware_class/README @@ -105,20 +105,3 @@ on the setup, so I think that the choice on what firmware to make persistent should be left to userspace. - - Why register_firmware()+__init can be useful: - - For boot devices needing firmware. - - To make the transition easier: - The firmware can be declared __init and register_firmware() - called on module_init. Then the firmware is warranted to be - there even if "firmware hotplug userspace" is not there yet or - it doesn't yet provide the needed firmware. - Once the firmware is widely available in userspace, it can be - removed from the kernel. Or made optional (CONFIG_.*_FIRMWARE). - - In either case, if firmware hotplug support is there, it can move the - firmware out of kernel memory into the real filesystem for later - usage. - - Note: If persistence is implemented on top of initramfs, - register_firmware() may not be appropriate. - diff --git a/Documentation/firmware_class/firmware_sample_driver.c b/Documentation/firmware_class/firmware_sample_driver.c index ad3edaba4533..87feccdb5c9f 100644 --- a/Documentation/firmware_class/firmware_sample_driver.c +++ b/Documentation/firmware_class/firmware_sample_driver.c @@ -5,8 +5,6 @@ * * Sample code on how to use request_firmware() from drivers. * - * Note that register_firmware() is currently useless. - * */ #include <linux/module.h> @@ -17,11 +15,6 @@ #include "linux/firmware.h" -#define WE_CAN_NEED_FIRMWARE_BEFORE_USERSPACE_IS_AVAILABLE -#ifdef WE_CAN_NEED_FIRMWARE_BEFORE_USERSPACE_IS_AVAILABLE -char __init inkernel_firmware[] = "let's say that this is firmware\n"; -#endif - static struct device ghost_device = { .bus_id = "ghost0", }; @@ -104,10 +97,6 @@ static void sample_probe_async(void) static int sample_init(void) { -#ifdef WE_CAN_NEED_FIRMWARE_BEFORE_USERSPACE_IS_AVAILABLE - register_firmware("sample_driver_fw", inkernel_firmware, - sizeof(inkernel_firmware)); -#endif device_initialize(&ghost_device); /* since there is no real hardware insertion I just call the * sample probe functions here */ diff --git a/Documentation/infiniband/ipoib.txt b/Documentation/infiniband/ipoib.txt index 5c5a4ccce76a..187035560d7f 100644 --- a/Documentation/infiniband/ipoib.txt +++ b/Documentation/infiniband/ipoib.txt @@ -1,10 +1,10 @@ IP OVER INFINIBAND The ib_ipoib driver is an implementation of the IP over InfiniBand - protocol as specified by the latest Internet-Drafts issued by the - IETF ipoib working group. It is a "native" implementation in the - sense of setting the interface type to ARPHRD_INFINIBAND and the - hardware address length to 20 (earlier proprietary implementations + protocol as specified by RFC 4391 and 4392, issued by the IETF ipoib + working group. It is a "native" implementation in the sense of + setting the interface type to ARPHRD_INFINIBAND and the hardware + address length to 20 (earlier proprietary implementations masqueraded to the kernel as ethernet interfaces). Partitions and P_Keys @@ -53,3 +53,7 @@ References IETF IP over InfiniBand (ipoib) Working Group http://ietf.org/html.charters/ipoib-charter.html + Transmission of IP over InfiniBand (IPoIB) (RFC 4391) + http://ietf.org/rfc/rfc4391.txt + IP over InfiniBand (IPoIB) Architecture (RFC 4392) + http://ietf.org/rfc/rfc4392.txt diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index b3a6187e5305..a9d3a1794b23 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -1402,6 +1402,15 @@ running once the system is up. If enabled at boot time, /selinux/disable can be used later to disable prior to initial policy load. + selinux_compat_net = + [SELINUX] Set initial selinux_compat_net flag value. + Format: { "0" | "1" } + 0 -- use new secmark-based packet controls + 1 -- use legacy packet controls + Default value is 0 (preferred). + Value can be changed at runtime via + /selinux/compat_net. + serialnumber [BUGS=IA-32] sg_def_reserved_size= [SCSI] diff --git a/Documentation/memory-barriers.txt b/Documentation/memory-barriers.txt index 92f0056d928c..4710845dbac4 100644 --- a/Documentation/memory-barriers.txt +++ b/Documentation/memory-barriers.txt @@ -19,6 +19,7 @@ Contents: - Control dependencies. - SMP barrier pairing. - Examples of memory barrier sequences. + - Read memory barriers vs load speculation. (*) Explicit kernel barriers. @@ -248,7 +249,7 @@ And there are a number of things that _must_ or _must_not_ be assumed: we may get either of: STORE *A = X; Y = LOAD *A; - STORE *A = Y; + STORE *A = Y = X; ========================= @@ -344,9 +345,12 @@ Memory barriers come in four basic varieties: (4) General memory barriers. - A general memory barrier is a combination of both a read memory barrier - and a write memory barrier. It is a partial ordering over both loads and - stores. + A general memory barrier gives a guarantee that all the LOAD and STORE + operations specified before the barrier will appear to happen before all + the LOAD and STORE operations specified after the barrier with respect to + the other components of the system. + + A general memory barrier is a partial ordering over both loads and stores. General memory barriers imply both read and write memory barriers, and so can substitute for either. @@ -546,9 +550,9 @@ write barrier, though, again, a general barrier is viable: =============== =============== a = 1; <write barrier> - b = 2; x = a; + b = 2; x = b; <read barrier> - y = b; + y = a; Or: @@ -563,6 +567,18 @@ Or: Basically, the read barrier always has to be there, even though it can be of the "weaker" type. +[!] Note that the stores before the write barrier would normally be expected to +match the loads after the read barrier or data dependency barrier, and vice +versa: + + CPU 1 CPU 2 + =============== =============== + a = 1; }---- --->{ v = c + b = 2; } \ / { w = d + <write barrier> \ <read barrier> + c = 3; } / \ { x = a; + d = 4; }---- --->{ y = b; + EXAMPLES OF MEMORY BARRIER SEQUENCES ------------------------------------ @@ -600,8 +616,8 @@ STORE B, STORE C } all occuring before the unordered set of { STORE D, STORE E | | +------+ +-------+ : : | - | Sequence in which stores committed to memory system - | by CPU 1 + | Sequence in which stores are committed to the + | memory system by CPU 1 V @@ -683,14 +699,12 @@ then the following will occur: | : : | | | : : | CPU 2 | | +-------+ | | - \ | X->9 |------>| | - \ +-------+ | | - ----->| B->2 | | | - +-------+ | | - Makes sure all effects ---> ddddddddddddddddd | | - prior to the store of C +-------+ | | - are perceptible to | B->2 |------>| | - successive loads +-------+ | | + | | X->9 |------>| | + | +-------+ | | + Makes sure all effects ---> \ ddddddddddddddddd | | + prior to the store of C \ +-------+ | | + are perceptible to ----->| B->2 |------>| | + subsequent loads +-------+ | | : : +-------+ @@ -699,73 +713,239 @@ following sequence of events: CPU 1 CPU 2 ======================= ======================= + { A = 0, B = 9 } STORE A=1 - STORE B=2 - STORE C=3 <write barrier> - STORE D=4 - STORE E=5 - LOAD A + STORE B=2 LOAD B - LOAD C - LOAD D - LOAD E + LOAD A Without intervention, CPU 2 may then choose to perceive the events on CPU 1 in some effectively random order, despite the write barrier issued by CPU 1: - +-------+ : : - | | +------+ - | |------>| C=3 | } - | | : +------+ } - | | : | A=1 | } - | | : +------+ } - | CPU 1 | : | B=2 | }--- - | | +------+ } \ - | | wwwwwwwwwwwww} \ - | | +------+ } \ : : +-------+ - | | : | E=5 | } \ +-------+ | | - | | : +------+ } \ { | C->3 |------>| | - | |------>| D=4 | } \ { +-------+ : | | - | | +------+ \ { | E->5 | : | | - +-------+ : : \ { +-------+ : | | - Transfer -->{ | A->1 | : | CPU 2 | - from CPU 1 { +-------+ : | | - to CPU 2 { | D->4 | : | | - { +-------+ : | | - { | B->2 |------>| | - +-------+ | | - : : +-------+ - - -If, however, a read barrier were to be placed between the load of C and the -load of D on CPU 2, then the partial ordering imposed by CPU 1 will be -perceived correctly by CPU 2. + +-------+ : : : : + | | +------+ +-------+ + | |------>| A=1 |------ --->| A->0 | + | | +------+ \ +-------+ + | CPU 1 | wwwwwwwwwwwwwwww \ --->| B->9 | + | | +------+ | +-------+ + | |------>| B=2 |--- | : : + | | +------+ \ | : : +-------+ + +-------+ : : \ | +-------+ | | + ---------->| B->2 |------>| | + | +-------+ | CPU 2 | + | | A->0 |------>| | + | +-------+ | | + | : : +-------+ + \ : : + \ +-------+ + ---->| A->1 | + +-------+ + : : - +-------+ : : - | | +------+ - | |------>| C=3 | } - | | : +------+ } - | | : | A=1 | }--- - | | : +------+ } \ - | CPU 1 | : | B=2 | } \ - | | +------+ \ - | | wwwwwwwwwwwwwwww \ - | | +------+ \ : : +-------+ - | | : | E=5 | } \ +-------+ | | - | | : +------+ }--- \ { | C->3 |------>| | - | |------>| D=4 | } \ \ { +-------+ : | | - | | +------+ \ -->{ | B->2 | : | | - +-------+ : : \ { +-------+ : | | - \ { | A->1 | : | CPU 2 | - \ +-------+ | | - At this point the read ----> \ rrrrrrrrrrrrrrrrr | | - barrier causes all effects \ +-------+ | | - prior to the storage of C \ { | E->5 | : | | - to be perceptible to CPU 2 -->{ +-------+ : | | - { | D->4 |------>| | - +-------+ | | - : : +-------+ + +If, however, a read barrier were to be placed between the load of E and the +load of A on CPU 2: + + CPU 1 CPU 2 + ======================= ======================= + { A = 0, B = 9 } + STORE A=1 + <write barrier> + STORE B=2 + LOAD B + <read barrier> + LOAD A + +then the partial ordering imposed by CPU 1 will be perceived correctly by CPU +2: + + +-------+ : : : : + | | +------+ +-------+ + | |------>| A=1 |------ --->| A->0 | + | | +------+ \ +-------+ + | CPU 1 | wwwwwwwwwwwwwwww \ --->| B->9 | + | | +------+ | +-------+ + | |------>| B=2 |--- | : : + | | +------+ \ | : : +-------+ + +-------+ : : \ | +-------+ | | + ---------->| B->2 |------>| | + | +-------+ | CPU 2 | + | : : | | + | : : | | + At this point the read ----> \ rrrrrrrrrrrrrrrrr | | + barrier causes all effects \ +-------+ | | + prior to the storage of B ---->| A->1 |------>| | + to be perceptible to CPU 2 +-------+ | | + : : +-------+ + + +To illustrate this more completely, consider what could happen if the code +contained a load of A either side of the read barrier: + + CPU 1 CPU 2 + ======================= ======================= + { A = 0, B = 9 } + STORE A=1 + <write barrier> + STORE B=2 + LOAD B + LOAD A [first load of A] + <read barrier> + LOAD A [second load of A] + +Even though the two loads of A both occur after the load of B, they may both +come up with different values: + + +-------+ : : : : + | | +------+ +-------+ + | |------>| A=1 |------ --->| A->0 | + | | +------+ \ +-------+ + | CPU 1 | wwwwwwwwwwwwwwww \ --->| B->9 | + | | +------+ | +-------+ + | |------>| B=2 |--- | : : + | | +------+ \ | : : +-------+ + +-------+ : : \ | +-------+ | | + ---------->| B->2 |------>| | + | +-------+ | CPU 2 | + | : : | | + | : : | | + | +-------+ | | + | | A->0 |------>| 1st | + | +-------+ | | + At this point the read ----> \ rrrrrrrrrrrrrrrrr | | + barrier causes all effects \ +-------+ | | + prior to the storage of B ---->| A->1 |------>| 2nd | + to be perceptible to CPU 2 +-------+ | | + : : +-------+ + + +But it may be that the update to A from CPU 1 becomes perceptible to CPU 2 +before the read barrier completes anyway: + + +-------+ : : : : + | | +------+ +-------+ + | |------>| A=1 |------ --->| A->0 | + | | +------+ \ +-------+ + | CPU 1 | wwwwwwwwwwwwwwww \ --->| B->9 | + | | +------+ | +-------+ + | |------>| B=2 |--- | : : + | | +------+ \ | : : +-------+ + +-------+ : : \ | +-------+ | | + ---------->| B->2 |------>| | + | +-------+ | CPU 2 | + | : : | | + \ : : | | + \ +-------+ | | + ---->| A->1 |------>| 1st | + +-------+ | | + rrrrrrrrrrrrrrrrr | | + +-------+ | | + | A->1 |------>| 2nd | + +-------+ | | + : : +-------+ + + +The guarantee is that the second load will always come up with A == 1 if the +load of B came up with B == 2. No such guarantee exists for the first load of +A; that may come up with either A == 0 or A == 1. + + +READ MEMORY BARRIERS VS LOAD SPECULATION +---------------------------------------- + +Many CPUs speculate with loads: that is they see that they will need to load an +item from memory, and they find a time where they're not using the bus for any +other loads, and so do the load in advance - even though they haven't actually +got to that point in the instruction execution flow yet. This permits the +actual load instruction to potentially complete immediately because the CPU +already has the value to hand. + +It may turn out that the CPU didn't actually need the value - perhaps because a +branch circumvented the load - in which case it can discard the value or just +cache it for later use. + +Consider: + + CPU 1 CPU 2 + ======================= ======================= + LOAD B + DIVIDE } Divide instructions generally + DIVIDE } take a long time to perform + LOAD A + +Which might appear as this: + + : : +-------+ + +-------+ | | + --->| B->2 |------>| | + +-------+ | CPU 2 | + : :DIVIDE | | + +-------+ | | + The CPU being busy doing a ---> --->| A->0 |~~~~ | | + division speculates on the +-------+ ~ | | + LOAD of A : : ~ | | + : :DIVIDE | | + : : ~ | | + Once the divisions are complete --> : : ~-->| | + the CPU can then perform the : : | | + LOAD with immediate effect : : +-------+ + + +Placing a read barrier or a data dependency barrier just before the second +load: + + CPU 1 CPU 2 + ======================= ======================= + LOAD B + DIVIDE + DIVIDE + <read barrier> + LOAD A + +will force any value speculatively obtained to be reconsidered to an extent +dependent on the type of barrier used. If there was no change made to the +speculated memory location, then the speculated value will just be used: + + : : +-------+ + +-------+ | | + --->| B->2 |------>| | + +-------+ | CPU 2 | + : :DIVIDE | | + +-------+ | | + The CPU being busy doing a ---> --->| A->0 |~~~~ | | + division speculates on the +-------+ ~ | | + LOAD of A : : ~ | | + : :DIVIDE | | + : : ~ | | + : : ~ | | + rrrrrrrrrrrrrrrr~ | | + : : ~ | | + : : ~-->| | + : : | | + : : +-------+ + + +but if there was an update or an invalidation from another CPU pending, then +the speculation will be cancelled and the value reloaded: + + : : +-------+ + +-------+ | | + --->| B->2 |------>| | + +-------+ | CPU 2 | + : :DIVIDE | | + +-------+ | | + The CPU being busy doing a ---> --->| A->0 |~~~~ | | + division speculates on the +-------+ ~ | | + LOAD of A : : ~ | | + : :DIVIDE | | + : : ~ | | + : : ~ | | + rrrrrrrrrrrrrrrrr | | + +-------+ | | + The speculation is discarded ---> --->| A->1 |------>| | + and an updated value is +-------+ | | + retrieved : : +-------+ ======================== @@ -901,7 +1081,7 @@ IMPLICIT KERNEL MEMORY BARRIERS =============================== Some of the other functions in the linux kernel imply memory barriers, amongst -which are locking, scheduling and memory allocation functions. +which are locking and scheduling functions. This specification is a _minimum_ guarantee; any particular architecture may provide more substantial guarantees, but these may not be relied upon outside @@ -966,6 +1146,20 @@ equivalent to a full barrier, but a LOCK followed by an UNLOCK is not. barriers is that the effects instructions outside of a critical section may seep into the inside of the critical section. +A LOCK followed by an UNLOCK may not be assumed to be full memory barrier +because it is possible for an access preceding the LOCK to happen after the +LOCK, and an access following the UNLOCK to happen before the UNLOCK, and the +two accesses can themselves then cross: + + *A = a; + LOCK + UNLOCK + *B = b; + +may occur as: + + LOCK, STORE *B, STORE *A, UNLOCK + Locks and semaphores may not provide any guarantee of ordering on UP compiled systems, and so cannot be counted on in such a situation to actually achieve anything at all - especially with respect to I/O accesses - unless combined @@ -1016,8 +1210,6 @@ Other functions that imply barriers: (*) schedule() and similar imply full memory barriers. - (*) Memory allocation and release functions imply full memory barriers. - ================================= INTER-CPU LOCKING BARRIER EFFECTS @@ -1031,7 +1223,7 @@ conflict on any particular lock. LOCKS VS MEMORY ACCESSES ------------------------ -Consider the following: the system has a pair of spinlocks (N) and (Q), and +Consider the following: the system has a pair of spinlocks (M) and (Q), and three CPUs; then should the following sequence of events occur: CPU 1 CPU 2 @@ -1678,7 +1870,7 @@ CPU's caches by some other cache event: smp_wmb(); <A:modify v=2> <C:busy> <C:queue v=2> - p = &b; q = p; + p = &v; q = p; <D:request p> <B:modify p=&v> <D:commit p=&v> <D:read p> diff --git a/Documentation/networking/README.ipw2200 b/Documentation/networking/README.ipw2200 index acb30c5dcff3..4f2a40f1dbc6 100644 --- a/Documentation/networking/README.ipw2200 +++ b/Documentation/networking/README.ipw2200 @@ -14,8 +14,8 @@ Copyright (C) 2004-2006, Intel Corporation README.ipw2200 -Version: 1.0.8 -Date : October 20, 2005 +Version: 1.1.2 +Date : March 30, 2006 Index @@ -103,7 +103,7 @@ file. 1.1. Overview of Features ----------------------------------------------- -The current release (1.0.8) supports the following features: +The current release (1.1.2) supports the following features: + BSS mode (Infrastructure, Managed) + IBSS mode (Ad-Hoc) @@ -247,8 +247,8 @@ and can set the contents via echo. For example: % cat /sys/bus/pci/drivers/ipw2200/debug_level Will report the current debug level of the driver's logging subsystem -(only available if CONFIG_IPW_DEBUG was configured when the driver was -built). +(only available if CONFIG_IPW2200_DEBUG was configured when the driver +was built). You can set the debug level via: diff --git a/Documentation/networking/bonding.txt b/Documentation/networking/bonding.txt index 8d8b4e5ea184..afac780445cd 100644 --- a/Documentation/networking/bonding.txt +++ b/Documentation/networking/bonding.txt @@ -1,7 +1,7 @@ Linux Ethernet Bonding Driver HOWTO - Latest update: 21 June 2005 + Latest update: 24 April 2006 Initial release : Thomas Davis <tadavis at lbl.gov> Corrections, HA extensions : 2000/10/03-15 : @@ -12,6 +12,8 @@ Corrections, HA extensions : 2000/10/03-15 : - Jay Vosburgh <fubar at us dot ibm dot com> Reorganized and updated Feb 2005 by Jay Vosburgh +Added Sysfs information: 2006/04/24 + - Mitch Williams <mitch.a.williams at intel.com> Introduction ============ @@ -38,61 +40,62 @@ Table of Contents 2. Bonding Driver Options 3. Configuring Bonding Devices -3.1 Configuration with sysconfig support -3.1.1 Using DHCP with sysconfig -3.1.2 Configuring Multiple Bonds with sysconfig -3.2 Configuration with initscripts support -3.2.1 Using DHCP with initscripts -3.2.2 Configuring Multiple Bonds with initscripts -3.3 Configuring Bonding Manually +3.1 Configuration with Sysconfig Support +3.1.1 Using DHCP with Sysconfig +3.1.2 Configuring Multiple Bonds with Sysconfig +3.2 Configuration with Initscripts Support +3.2.1 Using DHCP with Initscripts +3.2.2 Configuring Multiple Bonds with Initscripts +3.3 Configuring Bonding Manually with Ifenslave 3.3.1 Configuring Multiple Bonds Manually +3.4 Configuring Bonding Manually via Sysfs -5. Querying Bonding Configuration -5.1 Bonding Configuration -5.2 Network Configuration +4. Querying Bonding Configuration +4.1 Bonding Configuration +4.2 Network Configuration -6. Switch Configuration +5. Switch Configuration -7. 802.1q VLAN Support +6. 802.1q VLAN Support -8. Link Monitoring -8.1 ARP Monitor Operation -8.2 Configuring Multiple ARP Targets -8.3 MII Monitor Operation +7. Link Monitoring +7.1 ARP Monitor Operation +7.2 Configuring Multiple ARP Targets +7.3 MII Monitor Operation -9. Potential Trouble Sources -9.1 Adventures in Routing -9.2 Ethernet Device Renaming -9.3 Painfully Slow Or No Failed Link Detection By Miimon +8. Potential Trouble Sources +8.1 Adventures in Routing +8.2 Ethernet Device Renaming +8.3 Painfully Slow Or No Failed Link Detection By Miimon -10. SNMP agents +9. SNMP agents -11. Promiscuous mode +10. Promiscuous mode -12. Configuring Bonding for High Availability -12.1 High Availability in a Single Switch Topology -12.2 High Availability in a Multiple Switch Topology -12.2.1 HA Bonding Mode Selection for Multiple Switch Topology -12.2.2 HA Link Monitoring for Multiple Switch Topology +11. Configuring Bonding for High Availability +11.1 High Availability in a Single Switch Topology +11.2 High Availability in a Multiple Switch Topology +11.2.1 HA Bonding Mode Selection for Multiple Switch Topology +11.2.2 HA Link Monitoring for Multiple Switch Topology -13. Configuring Bonding for Maximum Throughput -13.1 Maximum Throughput in a Single Switch Topology -13.1.1 MT Bonding Mode Selection for Single Switch Topology -13.1.2 MT Link Monitoring for Single Switch Topology -13.2 Maximum Throughput in a Multiple Switch Topology -13.2.1 MT Bonding Mode Selection for Multiple Switch Topology -13.2.2 MT Link Monitoring for Multiple Switch Topology +12. Configuring Bonding for Maximum Throughput +12.1 Maximum Throughput in a Single Switch Topology +12.1.1 MT Bonding Mode Selection for Single Switch Topology +12.1.2 MT Link Monitoring for Single Switch Topology +12.2 Maximum Throughput in a Multiple Switch Topology +12.2.1 MT Bonding Mode Selection for Multiple Switch Topology +12.2.2 MT Link Monitoring for Multiple Switch Topology -14. Switch Behavior Issues -14.1 Link Establishment and Failover Delays -14.2 Duplicated Incoming Packets +13. Switch Behavior Issues +13.1 Link Establishment and Failover Delays +13.2 Duplicated Incoming Packets -15. Hardware Specific Considerations -15.1 IBM BladeCenter +14. Hardware Specific Considerations +14.1 IBM BladeCenter -16. Frequently Asked Questions +15. Frequently Asked Questions -17. Resources and Links +16. Resources and Links 1. Bonding Driver Installation @@ -156,6 +159,9 @@ you're trying to build it for. Some distros (e.g., Red Hat from 7.1 onwards) do not have /usr/include/linux symbolically linked to the default kernel source include directory. +SECOND IMPORTANT NOTE: + If you plan to configure bonding using sysfs, you do not need +to use ifenslave. 2. Bonding Driver Options ========================= @@ -270,7 +276,7 @@ mode In bonding version 2.6.2 or later, when a failover occurs in active-backup mode, bonding will issue one or more gratuitous ARPs on the newly active slave. - One gratutious ARP is issued for the bonding master + One gratuitous ARP is issued for the bonding master interface and each VLAN interfaces configured above it, provided that the interface has at least one IP address configured. Gratuitous ARPs issued for VLAN @@ -377,7 +383,7 @@ mode When a link is reconnected or a new slave joins the bond the receive traffic is redistributed among all active slaves in the bond by initiating ARP Replies - with the selected mac address to each of the + with the selected MAC address to each of the clients. The updelay parameter (detailed below) must be set to a value equal or greater than the switch's forwarding delay so that the ARP Replies sent to the @@ -498,11 +504,12 @@ not exist, and the layer2 policy is the only policy. 3. Configuring Bonding Devices ============================== - There are, essentially, two methods for configuring bonding: -with support from the distro's network initialization scripts, and -without. Distros generally use one of two packages for the network -initialization scripts: initscripts or sysconfig. Recent versions of -these packages have support for bonding, while older versions do not. + You can configure bonding using either your distro's network +initialization scripts, or manually using either ifenslave or the +sysfs interface. Distros generally use one of two packages for the +network initialization scripts: initscripts or sysconfig. Recent +versions of these packages have support for bonding, while older +versions do not. We will first describe the options for configuring bonding for distros using versions of initscripts and sysconfig with full or @@ -530,7 +537,7 @@ $ grep ifenslave /sbin/ifup If this returns any matches, then your initscripts or sysconfig has support for bonding. -3.1 Configuration with sysconfig support +3.1 Configuration with Sysconfig Support ---------------------------------------- This section applies to distros using a version of sysconfig @@ -538,7 +545,7 @@ with bonding support, for example, SuSE Linux Enterprise Server 9. SuSE SLES 9's networking configuration system does support bonding, however, at this writing, the YaST system configuration -frontend does not provide any means to work with bonding devices. +front end does not provide any means to work with bonding devices. Bonding devices can be managed by hand, however, as follows. First, if they have not already been configured, configure the @@ -660,7 +667,7 @@ format can be found in an example ifcfg template file: Note that the template does not document the various BONDING_ settings described above, but does describe many of the other options. -3.1.1 Using DHCP with sysconfig +3.1.1 Using DHCP with Sysconfig ------------------------------- Under sysconfig, configuring a device with BOOTPROTO='dhcp' @@ -670,7 +677,7 @@ attempt to obtain the device address from DHCP prior to adding any of the slave devices. Without active slaves, the DHCP requests are not sent to the network. -3.1.2 Configuring Multiple Bonds with sysconfig +3.1.2 Configuring Multiple Bonds with Sysconfig ----------------------------------------------- The sysconfig network initialization system is capable of @@ -685,7 +692,7 @@ ifcfg-bondX files. options in the ifcfg-bondX file, it is not necessary to add them to the system /etc/modules.conf or /etc/modprobe.conf configuration file. -3.2 Configuration with initscripts support +3.2 Configuration with Initscripts Support ------------------------------------------ This section applies to distros using a version of initscripts @@ -756,7 +763,7 @@ options for your configuration. will restart the networking subsystem and your bond link should be now up and running. -3.2.1 Using DHCP with initscripts +3.2.1 Using DHCP with Initscripts --------------------------------- Recent versions of initscripts (the version supplied with @@ -768,7 +775,7 @@ above, except replace the line "BOOTPROTO=none" with "BOOTPROTO=dhcp" and add a line consisting of "TYPE=Bonding". Note that the TYPE value is case sensitive. -3.2.2 Configuring Multiple Bonds with initscripts +3.2.2 Configuring Multiple Bonds with Initscripts ------------------------------------------------- At this writing, the initscripts package does not directly @@ -784,8 +791,8 @@ Fedora Core kernels, and has been seen on RHEL 4 as well. On kernels exhibiting this problem, it will be impossible to configure multiple bonds with differing parameters. -3.3 Configuring Bonding Manually --------------------------------- +3.3 Configuring Bonding Manually with Ifenslave +----------------------------------------------- This section applies to distros whose network initialization scripts (the sysconfig or initscripts package) do not have specific @@ -889,11 +896,139 @@ install bond1 /sbin/modprobe --ignore-install bonding -o bond1 \ This may be repeated any number of times, specifying a new and unique name in place of bond1 for each subsequent instance. +3.4 Configuring Bonding Manually via Sysfs +------------------------------------------ + + Starting with version 3.0, Channel Bonding may be configured +via the sysfs interface. This interface allows dynamic configuration +of all bonds in the system without unloading the module. It also +allows for adding and removing bonds at runtime. Ifenslave is no +longer required, though it is still supported. + + Use of the sysfs interface allows you to use multiple bonds +with different configurations without having to reload the module. +It also allows you to use multiple, differently configured bonds when +bonding is compiled into the kernel. + + You must have the sysfs filesystem mounted to configure +bonding this way. The examples in this document assume that you +are using the standard mount point for sysfs, e.g. /sys. If your +sysfs filesystem is mounted elsewhere, you will need to adjust the +example paths accordingly. + +Creating and Destroying Bonds +----------------------------- +To add a new bond foo: +# echo +foo > /sys/class/net/bonding_masters + +To remove an existing bond bar: +# echo -bar > /sys/class/net/bonding_masters + +To show all existing bonds: +# cat /sys/class/net/bonding_masters + +NOTE: due to 4K size limitation of sysfs files, this list may be +truncated if you have more than a few hundred bonds. This is unlikely +to occur under normal operating conditions. + +Adding and Removing Slaves +-------------------------- + Interfaces may be enslaved to a bond using the file +/sys/class/net/<bond>/bonding/slaves. The semantics for this file +are the same as for the bonding_masters file. + +To enslave interface eth0 to bond bond0: +# ifconfig bond0 up +# echo +eth0 > /sys/class/net/bond0/bonding/slaves + +To free slave eth0 from bond bond0: +# echo -eth0 > /sys/class/net/bond0/bonding/slaves + + NOTE: The bond must be up before slaves can be added. All +slaves are freed when the interface is brought down. + + When an interface is enslaved to a bond, symlinks between the +two are created in the sysfs filesystem. In this case, you would get +/sys/class/net/bond0/slave_eth0 pointing to /sys/class/net/eth0, and +/sys/class/net/eth0/master pointing to /sys/class/net/bond0. + + This means that you can tell quickly whether or not an +interface is enslaved by looking for the master symlink. Thus: +# echo -eth0 > /sys/class/net/eth0/master/bonding/slaves +will free eth0 from whatever bond it is enslaved to, regardless of +the name of the bond interface. + +Changing a Bond's Configuration +------------------------------- + Each bond may be configured individually by manipulating the +files located in /sys/class/net/<bond name>/bonding + + The names of these files correspond directly with the command- +line parameters described elsewhere in in this file, and, with the +exception of arp_ip_target, they accept the same values. To see the +current setting, simply cat the appropriate file. + + A few examples will be given here; for specific usage +guidelines for each parameter, see the appropriate section in this +document. + +To configure bond0 for balance-alb mode: +# ifconfig bond0 down +# echo 6 > /sys/class/net/bond0/bonding/mode + - or - +# echo balance-alb > /sys/class/net/bond0/bonding/mode + NOTE: The bond interface must be down before the mode can be +changed. + +To enable MII monitoring on bond0 with a 1 second interval: +# echo 1000 > /sys/class/net/bond0/bonding/miimon + NOTE: If ARP monitoring is enabled, it will disabled when MII +monitoring is enabled, and vice-versa. + +To add ARP targets: +# echo +192.168.0.100 > /sys/class/net/bond0/bonding/arp_ip_target +# echo +192.168.0.101 > /sys/class/net/bond0/bonding/arp_ip_target + NOTE: up to 10 target addresses may be specified. + +To remove an ARP target: +# echo -192.168.0.100 > /sys/class/net/bond0/bonding/arp_ip_target + +Example Configuration +--------------------- + We begin with the same example that is shown in section 3.3, +executed with sysfs, and without using ifenslave. + + To make a simple bond of two e100 devices (presumed to be eth0 +and eth1), and have it persist across reboots, edit the appropriate +file (/etc/init.d/boot.local or /etc/rc.d/rc.local), and add the +following: + +modprobe bonding +modprobe e100 +echo balance-alb > /sys/class/net/bond0/bonding/mode +ifconfig bond0 192.168.1.1 netmask 255.255.255.0 up +echo 100 > /sys/class/net/bond0/bonding/miimon +echo +eth0 > /sys/class/net/bond0/bonding/slaves +echo +eth1 > /sys/class/net/bond0/bonding/slaves + + To add a second bond, with two e1000 interfaces in +active-backup mode, using ARP monitoring, add the following lines to +your init script: + +modprobe e1000 +echo +bond1 > /sys/class/net/bonding_masters +echo active-backup > /sys/class/net/bond1/bonding/mode +ifconfig bond1 192.168.2.1 netmask 255.255.255.0 up +echo +192.168.2.100 /sys/class/net/bond1/bonding/arp_ip_target +echo 2000 > /sys/class/net/bond1/bonding/arp_interval +echo +eth2 > /sys/class/net/bond1/bonding/slaves +echo +eth3 > /sys/class/net/bond1/bonding/slaves + -5. Querying Bonding Configuration +4. Querying Bonding Configuration ================================= -5.1 Bonding Configuration +4.1 Bonding Configuration ------------------------- Each bonding device has a read-only file residing in the @@ -923,7 +1058,7 @@ generally as follows: The precise format and contents will change depending upon the bonding configuration, state, and version of the bonding driver. -5.2 Network configuration +4.2 Network configuration ------------------------- The network configuration can be inspected using the ifconfig @@ -958,7 +1093,7 @@ eth1 Link encap:Ethernet HWaddr 00:C0:F0:1F:37:B4 collisions:0 txqueuelen:100 Interrupt:9 Base address:0x1400 -6. Switch Configuration +5. Switch Configuration ======================= For this section, "switch" refers to whatever system the @@ -991,7 +1126,7 @@ transmit policy for an EtherChannel group; all three will interoperate with another EtherChannel group. -7. 802.1q VLAN Support +6. 802.1q VLAN Support ====================== It is possible to configure VLAN devices over a bond interface @@ -1042,7 +1177,7 @@ underlying device -- i.e. the bonding interface -- to promiscuous mode, which might not be what you want. -8. Link Monitoring +7. Link Monitoring ================== The bonding driver at present supports two schemes for @@ -1053,7 +1188,7 @@ monitor. bonding driver itself, it is not possible to enable both ARP and MII monitoring simultaneously. -8.1 ARP Monitor Operation +7.1 ARP Monitor Operation ------------------------- The ARP monitor operates as its name suggests: it sends ARP @@ -1071,7 +1206,7 @@ those slaves will stay down. If networking monitoring (tcpdump, etc) shows the ARP requests and replies on the network, then it may be that your device driver is not updating last_rx and trans_start. -8.2 Configuring Multiple ARP Targets +7.2 Configuring Multiple ARP Targets ------------------------------------ While ARP monitoring can be done with just one target, it can @@ -1094,7 +1229,7 @@ alias bond0 bonding options bond0 arp_interval=60 arp_ip_target=192.168.0.100 -8.3 MII Monitor Operation +7.3 MII Monitor Operation ------------------------- The MII monitor monitors only the carrier state of the local @@ -1120,14 +1255,14 @@ does not support or had some error in processing both the MII register and ethtool requests), then the MII monitor will assume the link is up. -9. Potential Sources of Trouble +8. Potential Sources of Trouble =============================== -9.1 Adventures in Routing +8.1 Adventures in Routing ------------------------- When bonding is configured, it is important that the slave -devices not have routes that supercede routes of the master (or, +devices not have routes that supersede routes of the master (or, generally, not have routes at all). For example, suppose the bonding device bond0 has two slaves, eth0 and eth1, and the routing table is as follows: @@ -1154,11 +1289,11 @@ by the state of the routing table. The solution here is simply to insure that slaves do not have routes of their own, and if for some reason they must, those routes do -not supercede routes of their master. This should generally be the +not supersede routes of their master. This should generally be the case, but unusual configurations or errant manual or automatic static route additions may cause trouble. -9.2 Ethernet Device Renaming +8.2 Ethernet Device Renaming ---------------------------- On systems with network configuration scripts that do not @@ -1207,7 +1342,7 @@ modprobe with --ignore-install to cause the normal action to then take place. Full documentation on this can be found in the modprobe.conf and modprobe manual pages. -9.3. Painfully Slow Or No Failed Link Detection By Miimon +8.3. Painfully Slow Or No Failed Link Detection By Miimon --------------------------------------------------------- By default, bonding enables the use_carrier option, which @@ -1235,7 +1370,7 @@ carrier state. It has no way to determine the state of devices on or beyond other ports of a switch, or if a switch is refusing to pass traffic while still maintaining carrier on. -10. SNMP agents +9. SNMP agents =============== If running SNMP agents, the bonding driver should be loaded @@ -1281,7 +1416,7 @@ ifDescr, the association between the IP address and IfIndex remains and SNMP functions such as Interface_Scan_Next will report that association. -11. Promiscuous mode +10. Promiscuous mode ==================== When running network monitoring tools, e.g., tcpdump, it is @@ -1308,7 +1443,7 @@ sending to peers that are unassigned or if the load is unbalanced. the active slave changes (e.g., due to a link failure), the promiscuous setting will be propagated to the new active slave. -12. Configuring Bonding for High Availability +11. Configuring Bonding for High Availability ============================================= High Availability refers to configurations that provide @@ -1318,7 +1453,7 @@ goal is to provide the maximum availability of network connectivity (i.e., the network always works), even though other configurations could provide higher throughput. -12.1 High Availability in a Single Switch Topology +11.1 High Availability in a Single Switch Topology -------------------------------------------------- If two hosts (or a host and a single switch) are directly @@ -1332,7 +1467,7 @@ the load will be rebalanced across the remaining devices. See Section 13, "Configuring Bonding for Maximum Throughput" for information on configuring bonding with one peer device. -12.2 High Availability in a Multiple Switch Topology +11.2 High Availability in a Multiple Switch Topology ---------------------------------------------------- With multiple switches, the configuration of bonding and the @@ -1359,7 +1494,7 @@ switches (ISL, or inter switch link), and multiple ports connecting to the outside world ("port3" on each switch). There is no technical reason that this could not be extended to a third switch. -12.2.1 HA Bonding Mode Selection for Multiple Switch Topology +11.2.1 HA Bonding Mode Selection for Multiple Switch Topology ------------------------------------------------------------- In a topology such as the example above, the active-backup and @@ -1381,7 +1516,7 @@ broadcast: This mode is really a special purpose mode, and is suitable necessary for some specific one-way traffic to reach both independent networks, then the broadcast mode may be suitable. -12.2.2 HA Link Monitoring Selection for Multiple Switch Topology +11.2.2 HA Link Monitoring Selection for Multiple Switch Topology ---------------------------------------------------------------- The choice of link monitoring ultimately depends upon your @@ -1402,10 +1537,10 @@ regardless of which switch is active, the ARP monitor has a suitable target to query. -13. Configuring Bonding for Maximum Throughput +12. Configuring Bonding for Maximum Throughput ============================================== -13.1 Maximizing Throughput in a Single Switch Topology +12.1 Maximizing Throughput in a Single Switch Topology ------------------------------------------------------ In a single switch configuration, the best method to maximize @@ -1476,7 +1611,7 @@ destination to make load balancing decisions. The behavior of each mode is described below. -13.1.1 MT Bonding Mode Selection for Single Switch Topology +12.1.1 MT Bonding Mode Selection for Single Switch Topology ----------------------------------------------------------- This configuration is the easiest to set up and to understand, @@ -1607,7 +1742,7 @@ balance-alb: This mode is everything that balance-tlb is, and more. device driver must support changing the hardware address while the device is open. -13.1.2 MT Link Monitoring for Single Switch Topology +12.1.2 MT Link Monitoring for Single Switch Topology ---------------------------------------------------- The choice of link monitoring may largely depend upon which @@ -1616,7 +1751,7 @@ support the use of the ARP monitor, and are thus restricted to using the MII monitor (which does not provide as high a level of end to end assurance as the ARP monitor). -13.2 Maximum Throughput in a Multiple Switch Topology +12.2 Maximum Throughput in a Multiple Switch Topology ----------------------------------------------------- Multiple switches may be utilized to optimize for throughput @@ -1651,7 +1786,7 @@ a single 72 port switch. can be equipped with an additional network device connected to an external network; this host then additionally acts as a gateway. -13.2.1 MT Bonding Mode Selection for Multiple Switch Topology +12.2.1 MT Bonding Mode Selection for Multiple Switch Topology ------------------------------------------------------------- In actual practice, the bonding mode typically employed in @@ -1664,7 +1799,7 @@ packets has arrived). When employed in this fashion, the balance-rr mode allows individual connections between two hosts to effectively utilize greater than one interface's bandwidth. -13.2.2 MT Link Monitoring for Multiple Switch Topology +12.2.2 MT Link Monitoring for Multiple Switch Topology ------------------------------------------------------ Again, in actual practice, the MII monitor is most often used @@ -1674,10 +1809,10 @@ advantages over the MII monitor are mitigated by the volume of probes needed as the number of systems involved grows (remember that each host in the network is configured with bonding). -14. Switch Behavior Issues +13. Switch Behavior Issues ========================== -14.1 Link Establishment and Failover Delays +13.1 Link Establishment and Failover Delays ------------------------------------------- Some switches exhibit undesirable behavior with regard to the @@ -1712,7 +1847,7 @@ switches take a long time to go into backup mode, it may be desirable to not activate a backup interface immediately after a link goes down. Failover may be delayed via the downdelay bonding module option. -14.2 Duplicated Incoming Packets +13.2 Duplicated Incoming Packets -------------------------------- It is not uncommon to observe a short burst of duplicated @@ -1751,14 +1886,14 @@ behavior, it can be induced by clearing the MAC forwarding table (on most Cisco switches, the privileged command "clear mac address-table dynamic" will accomplish this). -15. Hardware Specific Considerations +14. Hardware Specific Considerations ==================================== This section contains additional information for configuring bonding on specific hardware platforms, or for interfacing bonding with particular switches or other devices. -15.1 IBM BladeCenter +14.1 IBM BladeCenter -------------------- This applies to the JS20 and similar systems. @@ -1861,7 +1996,7 @@ bonding driver. avoid fail-over delay issues when using bonding. -16. Frequently Asked Questions +15. Frequently Asked Questions ============================== 1. Is it SMP safe? @@ -1925,7 +2060,7 @@ not have special switch requirements, but do need device drivers that support specific features (described in the appropriate section under module parameters, above). - In 802.3ad mode, it works with with systems that support IEEE + In 802.3ad mode, it works with systems that support IEEE 802.3ad Dynamic Link Aggregation. Most managed and many unmanaged switches currently available support 802.3ad. diff --git a/Documentation/networking/ip-sysctl.txt b/Documentation/networking/ip-sysctl.txt index f12007b80a46..d46338af6002 100644 --- a/Documentation/networking/ip-sysctl.txt +++ b/Documentation/networking/ip-sysctl.txt @@ -362,6 +362,13 @@ tcp_workaround_signed_windows - BOOLEAN not receive a window scaling option from them. Default: 0 +tcp_slow_start_after_idle - BOOLEAN + If set, provide RFC2861 behavior and time out the congestion + window after an idle period. An idle period is defined at + the current RTO. If unset, the congestion window will not + be timed out after an idle period. + Default: 1 + IP Variables: ip_local_port_range - 2 INTEGERS diff --git a/Documentation/networking/netdevices.txt b/Documentation/networking/netdevices.txt index 3c0a5ba614d7..847cedb238f6 100644 --- a/Documentation/networking/netdevices.txt +++ b/Documentation/networking/netdevices.txt @@ -42,9 +42,9 @@ dev->get_stats: Context: nominally process, but don't sleep inside an rwlock dev->hard_start_xmit: - Synchronization: dev->xmit_lock spinlock. + Synchronization: netif_tx_lock spinlock. When the driver sets NETIF_F_LLTX in dev->features this will be - called without holding xmit_lock. In this case the driver + called without holding netif_tx_lock. In this case the driver has to lock by itself when needed. It is recommended to use a try lock for this and return -1 when the spin lock fails. The locking there should also properly protect against @@ -62,12 +62,12 @@ dev->hard_start_xmit: Only valid when NETIF_F_LLTX is set. dev->tx_timeout: - Synchronization: dev->xmit_lock spinlock. + Synchronization: netif_tx_lock spinlock. Context: BHs disabled Notes: netif_queue_stopped() is guaranteed true dev->set_multicast_list: - Synchronization: dev->xmit_lock spinlock. + Synchronization: netif_tx_lock spinlock. Context: BHs disabled dev->poll: diff --git a/Documentation/networking/operstates.txt b/Documentation/networking/operstates.txt new file mode 100644 index 000000000000..4a21d9bb836b --- /dev/null +++ b/Documentation/networking/operstates.txt @@ -0,0 +1,161 @@ + +1. Introduction + +Linux distinguishes between administrative and operational state of an +interface. Admininstrative state is the result of "ip link set dev +<dev> up or down" and reflects whether the administrator wants to use +the device for traffic. + +However, an interface is not usable just because the admin enabled it +- ethernet requires to be plugged into the switch and, depending on +a site's networking policy and configuration, an 802.1X authentication +to be performed before user data can be transferred. Operational state +shows the ability of an interface to transmit this user data. + +Thanks to 802.1X, userspace must be granted the possibility to +influence operational state. To accommodate this, operational state is +split into two parts: Two flags that can be set by the driver only, and +a RFC2863 compatible state that is derived from these flags, a policy, +and changeable from userspace under certain rules. + + +2. Querying from userspace + +Both admin and operational state can be queried via the netlink +operation RTM_GETLINK. It is also possible to subscribe to RTMGRP_LINK +to be notified of updates. This is important for setting from userspace. + +These values contain interface state: + +ifinfomsg::if_flags & IFF_UP: + Interface is admin up +ifinfomsg::if_flags & IFF_RUNNING: + Interface is in RFC2863 operational state UP or UNKNOWN. This is for + backward compatibility, routing daemons, dhcp clients can use this + flag to determine whether they should use the interface. +ifinfomsg::if_flags & IFF_LOWER_UP: + Driver has signaled netif_carrier_on() +ifinfomsg::if_flags & IFF_DORMANT: + Driver has signaled netif_dormant_on() + +These interface flags can also be queried without netlink using the +SIOCGIFFLAGS ioctl. + +TLV IFLA_OPERSTATE + +contains RFC2863 state of the interface in numeric representation: + +IF_OPER_UNKNOWN (0): + Interface is in unknown state, neither driver nor userspace has set + operational state. Interface must be considered for user data as + setting operational state has not been implemented in every driver. +IF_OPER_NOTPRESENT (1): + Unused in current kernel (notpresent interfaces normally disappear), + just a numerical placeholder. +IF_OPER_DOWN (2): + Interface is unable to transfer data on L1, f.e. ethernet is not + plugged or interface is ADMIN down. +IF_OPER_LOWERLAYERDOWN (3): + Interfaces stacked on an interface that is IF_OPER_DOWN show this + state (f.e. VLAN). +IF_OPER_TESTING (4): + Unused in current kernel. +IF_OPER_DORMANT (5): + Interface is L1 up, but waiting for an external event, f.e. for a + protocol to establish. (802.1X) +IF_OPER_UP (6): + Interface is operational up and can be used. + +This TLV can also be queried via sysfs. + +TLV IFLA_LINKMODE + +contains link policy. This is needed for userspace interaction +described below. + +This TLV can also be queried via sysfs. + + +3. Kernel driver API + +Kernel drivers have access to two flags that map to IFF_LOWER_UP and +IFF_DORMANT. These flags can be set from everywhere, even from +interrupts. It is guaranteed that only the driver has write access, +however, if different layers of the driver manipulate the same flag, +the driver has to provide the synchronisation needed. + +__LINK_STATE_NOCARRIER, maps to !IFF_LOWER_UP: + +The driver uses netif_carrier_on() to clear and netif_carrier_off() to +set this flag. On netif_carrier_off(), the scheduler stops sending +packets. The name 'carrier' and the inversion are historical, think of +it as lower layer. + +netif_carrier_ok() can be used to query that bit. + +__LINK_STATE_DORMANT, maps to IFF_DORMANT: + +Set by the driver to express that the device cannot yet be used +because some driver controlled protocol establishment has to +complete. Corresponding functions are netif_dormant_on() to set the +flag, netif_dormant_off() to clear it and netif_dormant() to query. + +On device allocation, networking core sets the flags equivalent to +netif_carrier_ok() and !netif_dormant(). + + +Whenever the driver CHANGES one of these flags, a workqueue event is +scheduled to translate the flag combination to IFLA_OPERSTATE as +follows: + +!netif_carrier_ok(): + IF_OPER_LOWERLAYERDOWN if the interface is stacked, IF_OPER_DOWN + otherwise. Kernel can recognise stacked interfaces because their + ifindex != iflink. + +netif_carrier_ok() && netif_dormant(): + IF_OPER_DORMANT + +netif_carrier_ok() && !netif_dormant(): + IF_OPER_UP if userspace interaction is disabled. Otherwise + IF_OPER_DORMANT with the possibility for userspace to initiate the + IF_OPER_UP transition afterwards. + + +4. Setting from userspace + +Applications have to use the netlink interface to influence the +RFC2863 operational state of an interface. Setting IFLA_LINKMODE to 1 +via RTM_SETLINK instructs the kernel that an interface should go to +IF_OPER_DORMANT instead of IF_OPER_UP when the combination +netif_carrier_ok() && !netif_dormant() is set by the +driver. Afterwards, the userspace application can set IFLA_OPERSTATE +to IF_OPER_DORMANT or IF_OPER_UP as long as the driver does not set +netif_carrier_off() or netif_dormant_on(). Changes made by userspace +are multicasted on the netlink group RTMGRP_LINK. + +So basically a 802.1X supplicant interacts with the kernel like this: + +-subscribe to RTMGRP_LINK +-set IFLA_LINKMODE to 1 via RTM_SETLINK +-query RTM_GETLINK once to get initial state +-if initial flags are not (IFF_LOWER_UP && !IFF_DORMANT), wait until + netlink multicast signals this state +-do 802.1X, eventually abort if flags go down again +-send RTM_SETLINK to set operstate to IF_OPER_UP if authentication + succeeds, IF_OPER_DORMANT otherwise +-see how operstate and IFF_RUNNING is echoed via netlink multicast +-set interface back to IF_OPER_DORMANT if 802.1X reauthentication + fails +-restart if kernel changes IFF_LOWER_UP or IFF_DORMANT flag + +if supplicant goes down, bring back IFLA_LINKMODE to 0 and +IFLA_OPERSTATE to a sane value. + +A routing daemon or dhcp client just needs to care for IFF_RUNNING or +waiting for operstate to go IF_OPER_UP/IF_OPER_UNKNOWN before +considering the interface / querying a DHCP address. + + +For technical questions and/or comments please e-mail to Stefan Rompf +(stefan at loplof.de). diff --git a/Documentation/pci.txt b/Documentation/pci.txt index 711210b38f5f..66bbbf1d1ef6 100644 --- a/Documentation/pci.txt +++ b/Documentation/pci.txt @@ -259,7 +259,17 @@ on the bus need to be capable of doing it, so this is something which needs to be handled by platform and generic code, not individual drivers. -8. Obsolete functions +8. Vendor and device identifications +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ +For the future, let's avoid adding device ids to include/linux/pci_ids.h. + +PCI_VENDOR_ID_xxx for vendors, and a hex constant for device ids. + +Rationale: PCI_VENDOR_ID_xxx constants are re-used, but device ids are not. + Further, device ids are arbitrary hex numbers, normally used only in a + single location, the pci_device_id table. + +9. Obsolete functions ~~~~~~~~~~~~~~~~~~~~~ There are several functions which you might come across when trying to port an old driver to the new PCI interface. They are no longer present diff --git a/Documentation/power/video.txt b/Documentation/power/video.txt index d18a57d1a531..43a889f8f08d 100644 --- a/Documentation/power/video.txt +++ b/Documentation/power/video.txt @@ -140,7 +140,7 @@ IBM TP T41p s3_bios (2), switch to X after resume IBM TP T42 s3_bios (2) IBM ThinkPad T42p (2373-GTG) s3_bios (2) IBM TP X20 ??? (*) -IBM TP X30 s3_bios (2) +IBM TP X30 s3_bios, s3_mode (4) IBM TP X31 / Type 2672-XXH none (1), use radeontool (http://fdd.com/software/radeon/) to turn off backlight. IBM TP X32 none (1), but backlight is on and video is trashed after long suspend. s3_bios,s3_mode (4) works too. Perhaps that gets better results? IBM Thinkpad X40 Type 2371-7JG s3_bios,s3_mode (4) diff --git a/Documentation/scsi/ChangeLog.megaraid b/Documentation/scsi/ChangeLog.megaraid index 09f6300eda4b..c173806c91fa 100644 --- a/Documentation/scsi/ChangeLog.megaraid +++ b/Documentation/scsi/ChangeLog.megaraid @@ -1,3 +1,28 @@ +Release Date : Mon Apr 11 12:27:22 EST 2006 - Seokmann Ju <sju@lsil.com> +Current Version : 2.20.4.8 (scsi module), 2.20.2.6 (cmm module) +Older Version : 2.20.4.7 (scsi module), 2.20.2.6 (cmm module) + +1. Fixed a bug in megaraid_reset_handler(). + Customer reported "Unable to handle kernel NULL pointer dereference + at virtual address 00000000" when system goes to reset condition + for some reason. It happened randomly. + Root Cause: in the megaraid_reset_handler(), there is possibility not + returning pending packets in the pend_list if there are multiple + pending packets. + Fix: Made the change in the driver so that it will return all packets + in the pend_list. + +2. Added change request. + As found in the following URL, rmb() only didn't help the + problem. I had to increase the loop counter to 0xFFFFFF. (6 F's) + http://marc.theaimsgroup.com/?l=linux-scsi&m=110971060502497&w=2 + + I attached a patch for your reference, too. + Could you check and get this fix in your driver? + + Best Regards, + Jun'ichi Nomura + Release Date : Fri Nov 11 12:27:22 EST 2005 - Seokmann Ju <sju@lsil.com> Current Version : 2.20.4.7 (scsi module), 2.20.2.6 (cmm module) Older Version : 2.20.4.6 (scsi module), 2.20.2.6 (cmm module) diff --git a/Documentation/serial/driver b/Documentation/serial/driver index df82116a9f26..88ad615dd338 100644 --- a/Documentation/serial/driver +++ b/Documentation/serial/driver @@ -214,12 +214,13 @@ hardware. The interaction of the iflag bits is as follows (parity error given as an example): Parity error INPCK IGNPAR - None n/a n/a character received - Yes n/a 0 character discarded - Yes 0 1 character received, marked as + n/a 0 n/a character received, marked as TTY_NORMAL - Yes 1 1 character received, marked as + None 1 n/a character received, marked as + TTY_NORMAL + Yes 1 0 character received, marked as TTY_PARITY + Yes 1 1 character discarded Other flags may be used (eg, xon/xoff characters) if your hardware supports hardware "soft" flow control. diff --git a/Documentation/sound/alsa/Audiophile-Usb.txt b/Documentation/sound/alsa/Audiophile-Usb.txt index 4692c8e77dc1..b535c2a198f8 100644 --- a/Documentation/sound/alsa/Audiophile-Usb.txt +++ b/Documentation/sound/alsa/Audiophile-Usb.txt @@ -1,4 +1,4 @@ - Guide to using M-Audio Audiophile USB with ALSA and Jack v1.2 + Guide to using M-Audio Audiophile USB with ALSA and Jack v1.3 ======================================================== Thibault Le Meur <Thibault.LeMeur@supelec.fr> @@ -22,16 +22,16 @@ The device has 4 audio interfaces, and 2 MIDI ports: * Midi In (Mi) * Midi Out (Mo) -The internal DAC/ADC has the following caracteristics: +The internal DAC/ADC has the following characteristics: * sample depth of 16 or 24 bits * sample rate from 8kHz to 96kHz -* Two ports can't use different sample depths at the same time.Moreover, the +* Two ports can't use different sample depths at the same time. Moreover, the Audiophile USB documentation gives the following Warning: "Please exit any audio application running before switching between bit depths" Due to the USB 1.1 bandwidth limitation, a limited number of interfaces can be activated at the same time depending on the audio mode selected: - * 16-bit/48kHz ==> 4 channels in/ 4 channels out + * 16-bit/48kHz ==> 4 channels in/4 channels out - Ai+Ao+Di+Do * 24-bit/48kHz ==> 4 channels in/2 channels out, or 2 channels in/4 channels out @@ -41,8 +41,8 @@ activated at the same time depending on the audio mode selected: Important facts about the Digital interface: -------------------------------------------- - * The Do port additionnaly supports surround-encoded AC-3 and DTS passthrough, -though I haven't tested it under linux + * The Do port additionally supports surround-encoded AC-3 and DTS passthrough, +though I haven't tested it under Linux - Note that in this setup only the Do interface can be enabled * Apart from recording an audio digital stream, enabling the Di port is a way to synchronize the device to an external sample clock @@ -60,24 +60,23 @@ synchronization error (for instance sound played at an odd sample rate) The Audiophile USB MIDI ports will be automatically supported once the following modules have been loaded: * snd-usb-audio - * snd-seq * snd-seq-midi -No additionnal setting is required. +No additional setting is required. 2.2 - Audio ports ----------------- Audio functions of the Audiophile USB device are handled by the snd-usb-audio module. This module can work in a default mode (without any device-specific -parameter), or in an advanced mode with the device-specific parameter called +parameter), or in an "advanced" mode with the device-specific parameter called "device_setup". 2.2.1 - Default Alsa driver mode -The default behaviour of the snd-usb-audio driver is to parse the device +The default behavior of the snd-usb-audio driver is to parse the device capabilities at startup and enable all functions inside the device (including -all ports at any sample rates and any sample depths supported). This approach +all ports at any supported sample rates and sample depths). This approach has the advantage to let the driver easily switch from sample rates/depths automatically according to the need of the application claiming the device. @@ -114,9 +113,9 @@ gain). For people having this problem, the snd-usb-audio module has a new module parameter called "device_setup". -2.2.2.1 - Initializing the working mode of the Audiohile USB +2.2.2.1 - Initializing the working mode of the Audiophile USB -As far as the Audiohile USB device is concerned, this value let the user +As far as the Audiophile USB device is concerned, this value let the user specify: * the sample depth * the sample rate @@ -174,20 +173,20 @@ The parameter can be given: IMPORTANT NOTE WHEN SWITCHING CONFIGURATION: ------------------------------------------- - * You may need to _first_ intialize the module with the correct device_setup + * You may need to _first_ initialize the module with the correct device_setup parameter and _only_after_ turn on the Audiophile USB device * This is especially true when switching the sample depth: - - first trun off the device - - de-register the snd-usb-audio module - - change the device_setup parameter (by either manually reprobing the module - or changing modprobe.conf) + - first turn off the device + - de-register the snd-usb-audio module (modprobe -r) + - change the device_setup parameter by changing the device_setup + option in /etc/modprobe.conf - turn on the device 2.2.2.3 - Audiophile USB's device_setup structure If you want to understand the device_setup magic numbers for the Audiophile USB, you need some very basic understanding of binary computation. However, -this is not required to use the parameter and you may skip thi section. +this is not required to use the parameter and you may skip this section. The device_setup is one byte long and its structure is the following: @@ -231,11 +230,11 @@ Caution: 2.2.3 - USB implementation details for this device -You may safely skip this section if you're not interrested in driver +You may safely skip this section if you're not interested in driver development. -This section describes some internals aspect of the device and summarize the -data I got by usb-snooping the windows and linux drivers. +This section describes some internal aspects of the device and summarize the +data I got by usb-snooping the windows and Linux drivers. The M-Audio Audiophile USB has 7 USB Interfaces: a "USB interface": @@ -277,9 +276,9 @@ Here is a short description of the AltSettings capabilities: - 16-bit depth, 8-48kHz sample mode - Synch playback (Do), audio format type III IEC1937_AC-3 -In order to ensure a correct intialization of the device, the driver +In order to ensure a correct initialization of the device, the driver _must_know_ how the device will be used: - * if DTS is choosen, only Interface 2 with AltSet nb.6 must be + * if DTS is chosen, only Interface 2 with AltSet nb.6 must be registered * if 96KHz only AltSets nb.1 of each interface must be selected * if samples are using 24bits/48KHz then AltSet 2 must me used if @@ -290,7 +289,7 @@ _must_know_ how the device will be used: is not connected When device_setup is given as a parameter to the snd-usb-audio module, the -parse_audio_enpoint function uses a quirk called +parse_audio_endpoints function uses a quirk called "audiophile_skip_setting_quirk" in order to prevent AltSettings not corresponding to device_setup from being registered in the driver. @@ -317,9 +316,8 @@ However you may see the following warning message: using the "default" ALSA device. This is less efficient than it could be. Consider using a hardware device instead rather than using the plug layer." - 3.2 - Patching alsa to use direct pcm device -------------------------------------------- +-------------------------------------------- A patch for Jack by Andreas Steinmetz adds support for Big Endian devices. However it has not been included in the CVS tree. @@ -331,3 +329,32 @@ After having applied the patch you can run jackd with the following command line: % jackd -R -dalsa -Phw:1,0 -r48000 -p128 -n2 -D -Chw:1,1 +3.2 - Getting 2 input and/or output interfaces in Jack +------------------------------------------------------ + +As you can see, starting the Jack server this way will only enable 1 stereo +input (Di or Ai) and 1 stereo output (Ao or Do). + +This is due to the following restrictions: +* Jack can only open one capture device and one playback device at a time +* The Audiophile USB is seen as 2 (or three) Alsa devices: hw:1,0, hw:1,1 + (and optionally hw:1,2) +If you want to get Ai+Di and/or Ao+Do support with Jack, you would need to +combine the Alsa devices into one logical "complex" device. + +If you want to give it a try, I recommend reading the information from +this page: http://www.sound-man.co.uk/linuxaudio/ice1712multi.html +It is related to another device (ice1712) but can be adapted to suit +the Audiophile USB. + +Enabling multiple Audiophile USB interfaces for Jackd will certainly require: +* patching Jack with the previously mentioned "Big Endian" patch +* patching Jackd with the MMAP_COMPLEX patch (see the ice1712 page) +* patching the alsa-lib/src/pcm/pcm_multi.c file (see the ice1712 page) +* define a multi device (combination of hw:1,0 and hw:1,1) in your .asoundrc + file +* start jackd with this device + +I had no success in testing this for now, but this may be due to my OS +configuration. If you have any success with this kind of setup, please +drop me an email. diff --git a/Documentation/sound/alsa/DocBook/writing-an-alsa-driver.tmpl b/Documentation/sound/alsa/DocBook/writing-an-alsa-driver.tmpl index 68eeebc17ff4..1faf76383bab 100644 --- a/Documentation/sound/alsa/DocBook/writing-an-alsa-driver.tmpl +++ b/Documentation/sound/alsa/DocBook/writing-an-alsa-driver.tmpl @@ -1172,7 +1172,7 @@ } /* PCI IDs */ - static struct pci_device_id snd_mychip_ids[] = { + static struct pci_device_id snd_mychip_ids[] __devinitdata = { { PCI_VENDOR_ID_FOO, PCI_DEVICE_ID_BAR, PCI_ANY_ID, PCI_ANY_ID, 0, 0, 0, }, .... @@ -1565,7 +1565,7 @@ <informalexample> <programlisting> <![CDATA[ - static struct pci_device_id snd_mychip_ids[] = { + static struct pci_device_id snd_mychip_ids[] __devinitdata = { { PCI_VENDOR_ID_FOO, PCI_DEVICE_ID_BAR, PCI_ANY_ID, PCI_ANY_ID, 0, 0, 0, }, .... diff --git a/Documentation/spi/pxa2xx b/Documentation/spi/pxa2xx new file mode 100644 index 000000000000..9c45f3df2e18 --- /dev/null +++ b/Documentation/spi/pxa2xx @@ -0,0 +1,234 @@ +PXA2xx SPI on SSP driver HOWTO +=================================================== +This a mini howto on the pxa2xx_spi driver. The driver turns a PXA2xx +synchronous serial port into a SPI master controller +(see Documentation/spi/spi_summary). The driver has the following features + +- Support for any PXA2xx SSP +- SSP PIO and SSP DMA data transfers. +- External and Internal (SSPFRM) chip selects. +- Per slave device (chip) configuration. +- Full suspend, freeze, resume support. + +The driver is built around a "spi_message" fifo serviced by workqueue and a +tasklet. The workqueue, "pump_messages", drives message fifo and the tasklet +(pump_transfer) is responsible for queuing SPI transactions and setting up and +launching the dma/interrupt driven transfers. + +Declaring PXA2xx Master Controllers +----------------------------------- +Typically a SPI master is defined in the arch/.../mach-*/board-*.c as a +"platform device". The master configuration is passed to the driver via a table +found in include/asm-arm/arch-pxa/pxa2xx_spi.h: + +struct pxa2xx_spi_master { + enum pxa_ssp_type ssp_type; + u32 clock_enable; + u16 num_chipselect; + u8 enable_dma; +}; + +The "pxa2xx_spi_master.ssp_type" field must have a value between 1 and 3 and +informs the driver which features a particular SSP supports. + +The "pxa2xx_spi_master.clock_enable" field is used to enable/disable the +corresponding SSP peripheral block in the "Clock Enable Register (CKEN"). See +the "PXA2xx Developer Manual" section "Clocks and Power Management". + +The "pxa2xx_spi_master.num_chipselect" field is used to determine the number of +slave device (chips) attached to this SPI master. + +The "pxa2xx_spi_master.enable_dma" field informs the driver that SSP DMA should +be used. This caused the driver to acquire two DMA channels: rx_channel and +tx_channel. The rx_channel has a higher DMA service priority the tx_channel. +See the "PXA2xx Developer Manual" section "DMA Controller". + +NSSP MASTER SAMPLE +------------------ +Below is a sample configuration using the PXA255 NSSP. + +static struct resource pxa_spi_nssp_resources[] = { + [0] = { + .start = __PREG(SSCR0_P(2)), /* Start address of NSSP */ + .end = __PREG(SSCR0_P(2)) + 0x2c, /* Range of registers */ + .flags = IORESOURCE_MEM, + }, + [1] = { + .start = IRQ_NSSP, /* NSSP IRQ */ + .end = IRQ_NSSP, + .flags = IORESOURCE_IRQ, + }, +}; + +static struct pxa2xx_spi_master pxa_nssp_master_info = { + .ssp_type = PXA25x_NSSP, /* Type of SSP */ + .clock_enable = CKEN9_NSSP, /* NSSP Peripheral clock */ + .num_chipselect = 1, /* Matches the number of chips attached to NSSP */ + .enable_dma = 1, /* Enables NSSP DMA */ +}; + +static struct platform_device pxa_spi_nssp = { + .name = "pxa2xx-spi", /* MUST BE THIS VALUE, so device match driver */ + .id = 2, /* Bus number, MUST MATCH SSP number 1..n */ + .resource = pxa_spi_nssp_resources, + .num_resources = ARRAY_SIZE(pxa_spi_nssp_resources), + .dev = { + .platform_data = &pxa_nssp_master_info, /* Passed to driver */ + }, +}; + +static struct platform_device *devices[] __initdata = { + &pxa_spi_nssp, +}; + +static void __init board_init(void) +{ + (void)platform_add_device(devices, ARRAY_SIZE(devices)); +} + +Declaring Slave Devices +----------------------- +Typically each SPI slave (chip) is defined in the arch/.../mach-*/board-*.c +using the "spi_board_info" structure found in "linux/spi/spi.h". See +"Documentation/spi/spi_summary" for additional information. + +Each slave device attached to the PXA must provide slave specific configuration +information via the structure "pxa2xx_spi_chip" found in +"include/asm-arm/arch-pxa/pxa2xx_spi.h". The pxa2xx_spi master controller driver +will uses the configuration whenever the driver communicates with the slave +device. + +struct pxa2xx_spi_chip { + u8 tx_threshold; + u8 rx_threshold; + u8 dma_burst_size; + u32 timeout_microsecs; + u8 enable_loopback; + void (*cs_control)(u32 command); +}; + +The "pxa2xx_spi_chip.tx_threshold" and "pxa2xx_spi_chip.rx_threshold" fields are +used to configure the SSP hardware fifo. These fields are critical to the +performance of pxa2xx_spi driver and misconfiguration will result in rx +fifo overruns (especially in PIO mode transfers). Good default values are + + .tx_threshold = 12, + .rx_threshold = 4, + +The "pxa2xx_spi_chip.dma_burst_size" field is used to configure PXA2xx DMA +engine and is related the "spi_device.bits_per_word" field. Read and understand +the PXA2xx "Developer Manual" sections on the DMA controller and SSP Controllers +to determine the correct value. An SSP configured for byte-wide transfers would +use a value of 8. + +The "pxa2xx_spi_chip.timeout_microsecs" fields is used to efficiently handle +trailing bytes in the SSP receiver fifo. The correct value for this field is +dependent on the SPI bus speed ("spi_board_info.max_speed_hz") and the specific +slave device. Please note the the PXA2xx SSP 1 does not support trailing byte +timeouts and must busy-wait any trailing bytes. + +The "pxa2xx_spi_chip.enable_loopback" field is used to place the SSP porting +into internal loopback mode. In this mode the SSP controller internally +connects the SSPTX pin the the SSPRX pin. This is useful for initial setup +testing. + +The "pxa2xx_spi_chip.cs_control" field is used to point to a board specific +function for asserting/deasserting a slave device chip select. If the field is +NULL, the pxa2xx_spi master controller driver assumes that the SSP port is +configured to use SSPFRM instead. + +NSSP SALVE SAMPLE +----------------- +The pxa2xx_spi_chip structure is passed to the pxa2xx_spi driver in the +"spi_board_info.controller_data" field. Below is a sample configuration using +the PXA255 NSSP. + +/* Chip Select control for the CS8415A SPI slave device */ +static void cs8415a_cs_control(u32 command) +{ + if (command & PXA2XX_CS_ASSERT) + GPCR(2) = GPIO_bit(2); + else + GPSR(2) = GPIO_bit(2); +} + +/* Chip Select control for the CS8405A SPI slave device */ +static void cs8405a_cs_control(u32 command) +{ + if (command & PXA2XX_CS_ASSERT) + GPCR(3) = GPIO_bit(3); + else + GPSR(3) = GPIO_bit(3); +} + +static struct pxa2xx_spi_chip cs8415a_chip_info = { + .tx_threshold = 12, /* SSP hardward FIFO threshold */ + .rx_threshold = 4, /* SSP hardward FIFO threshold */ + .dma_burst_size = 8, /* Byte wide transfers used so 8 byte bursts */ + .timeout_microsecs = 64, /* Wait at least 64usec to handle trailing */ + .cs_control = cs8415a_cs_control, /* Use external chip select */ +}; + +static struct pxa2xx_spi_chip cs8405a_chip_info = { + .tx_threshold = 12, /* SSP hardward FIFO threshold */ + .rx_threshold = 4, /* SSP hardward FIFO threshold */ + .dma_burst_size = 8, /* Byte wide transfers used so 8 byte bursts */ + .timeout_microsecs = 64, /* Wait at least 64usec to handle trailing */ + .cs_control = cs8405a_cs_control, /* Use external chip select */ +}; + +static struct spi_board_info streetracer_spi_board_info[] __initdata = { + { + .modalias = "cs8415a", /* Name of spi_driver for this device */ + .max_speed_hz = 3686400, /* Run SSP as fast a possbile */ + .bus_num = 2, /* Framework bus number */ + .chip_select = 0, /* Framework chip select */ + .platform_data = NULL; /* No spi_driver specific config */ + .controller_data = &cs8415a_chip_info, /* Master chip config */ + .irq = STREETRACER_APCI_IRQ, /* Slave device interrupt */ + }, + { + .modalias = "cs8405a", /* Name of spi_driver for this device */ + .max_speed_hz = 3686400, /* Run SSP as fast a possbile */ + .bus_num = 2, /* Framework bus number */ + .chip_select = 1, /* Framework chip select */ + .controller_data = &cs8405a_chip_info, /* Master chip config */ + .irq = STREETRACER_APCI_IRQ, /* Slave device interrupt */ + }, +}; + +static void __init streetracer_init(void) +{ + spi_register_board_info(streetracer_spi_board_info, + ARRAY_SIZE(streetracer_spi_board_info)); +} + + +DMA and PIO I/O Support +----------------------- +The pxa2xx_spi driver support both DMA and interrupt driven PIO message +transfers. The driver defaults to PIO mode and DMA transfers must enabled by +setting the "enable_dma" flag in the "pxa2xx_spi_master" structure and and +ensuring that the "pxa2xx_spi_chip.dma_burst_size" field is non-zero. The DMA +mode support both coherent and stream based DMA mappings. + +The following logic is used to determine the type of I/O to be used on +a per "spi_transfer" basis: + +if !enable_dma or dma_burst_size == 0 then + always use PIO transfers + +if spi_message.is_dma_mapped and rx_dma_buf != 0 and tx_dma_buf != 0 then + use coherent DMA mode + +if rx_buf and tx_buf are aligned on 8 byte boundary then + use streaming DMA mode + +otherwise + use PIO transfer + +THANKS TO +--------- + +David Brownell and others for mentoring the development of this driver. + diff --git a/Documentation/spi/spi-summary b/Documentation/spi/spi-summary index a5ffba33a351..068732d32276 100644 --- a/Documentation/spi/spi-summary +++ b/Documentation/spi/spi-summary @@ -414,7 +414,33 @@ to get the driver-private data allocated for that device. The driver will initialize the fields of that spi_master, including the bus number (maybe the same as the platform device ID) and three methods used to interact with the SPI core and SPI protocol drivers. It will -also initialize its own internal state. +also initialize its own internal state. (See below about bus numbering +and those methods.) + +After you initialize the spi_master, then use spi_register_master() to +publish it to the rest of the system. At that time, device nodes for +the controller and any predeclared spi devices will be made available, +and the driver model core will take care of binding them to drivers. + +If you need to remove your SPI controller driver, spi_unregister_master() +will reverse the effect of spi_register_master(). + + +BUS NUMBERING + +Bus numbering is important, since that's how Linux identifies a given +SPI bus (shared SCK, MOSI, MISO). Valid bus numbers start at zero. On +SOC systems, the bus numbers should match the numbers defined by the chip +manufacturer. For example, hardware controller SPI2 would be bus number 2, +and spi_board_info for devices connected to it would use that number. + +If you don't have such hardware-assigned bus number, and for some reason +you can't just assign them, then provide a negative bus number. That will +then be replaced by a dynamically assigned number. You'd then need to treat +this as a non-static configuration (see above). + + +SPI MASTER METHODS master->setup(struct spi_device *spi) This sets up the device clock rate, SPI mode, and word sizes. @@ -431,6 +457,9 @@ also initialize its own internal state. state it dynamically associates with that device. If you do that, be sure to provide the cleanup() method to free that state. + +SPI MESSAGE QUEUE + The bulk of the driver will be managing the I/O queue fed by transfer(). That queue could be purely conceptual. For example, a driver used only @@ -440,6 +469,9 @@ But the queue will probably be very real, using message->queue, PIO, often DMA (especially if the root filesystem is in SPI flash), and execution contexts like IRQ handlers, tasklets, or workqueues (such as keventd). Your driver can be as fancy, or as simple, as you need. +Such a transfer() method would normally just add the message to a +queue, and then start some asynchronous transfer engine (unless it's +already running). THANKS TO diff --git a/Documentation/watchdog/watchdog-api.txt b/Documentation/watchdog/watchdog-api.txt index c5beb548cfc4..21ed51173662 100644 --- a/Documentation/watchdog/watchdog-api.txt +++ b/Documentation/watchdog/watchdog-api.txt @@ -36,6 +36,9 @@ timeout or margin. The simplest way to ping the watchdog is to write some data to the device. So a very simple watchdog daemon would look like this: +#include <stdlib.h> +#include <fcntl.h> + int main(int argc, const char *argv[]) { int fd=open("/dev/watchdog",O_WRONLY); if (fd==-1) { |