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path: root/drivers/char/rocket.c (follow)
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2010-08-23rocket: add a mutex_unlock()Dan Carpenter1-0/+1
This path needs a mutex_unlock(). This is stuff from the bkl to mutex transition. Signed-off-by: Dan Carpenter <error27@gmail.com> Acked-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-08-10rocket: kill BKLAlan Cox1-9/+19
We can use the port mutex for this and also for the hangup path so removing the problematic use of the hangup mutex in this driver. Fix up the locking on the various port flags while we are at it. Ultimately this driver needs to be using tty_port_ helpers which would sort this out far better. Signed-off-by: Alan Cox <alan@linux.intel.com> Cc: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-07-12headers: smp_lock.h reduxAlexey Dobriyan1-0/+1
* Remove smp_lock.h from files which don't need it (including some headers!) * Add smp_lock.h to files which do need it * Make smp_lock.h include conditional in hardirq.h It's needed only for one kernel_locked() usage which is under CONFIG_PREEMPT This will make hardirq.h inclusion cheaper for every PREEMPT=n config (which includes allmodconfig/allyesconfig, BTW) Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-06-11rocket: fix test_bit parametersJiri Slaby1-3/+3
Switch from ASYNC_* to ASYNCB_*, because {test,set}_bit expect bit number, not mask. Signed-off-by: Jiri Slaby <jirislaby@gmail.com> Signed-off-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-06-11tty: Add carrier processing on close to the tty_port coreAlan Cox1-4/+9
Some drivers implement this internally, others miss it out. Push the behaviour into the core code as that way everyone will do it consistently. Update the dtr rts method to raise or lower depending upon flags. Having a single method in this style fits most of the implementations more cleanly than two funtions. We need this in place before we tackle the USB side Signed-off-by: Alan Cox <alan@lxorguk.ukuu.org.uk> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-01-02tty: use port methods for the rocket driverAlan Cox1-159/+18
Now we have our ducks in order we can begin switching to the port operations Signed-off-by: Alan Cox <alan@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-01-02tty: kref the rocket driverAlan Cox1-37/+41
We will need this kref fitted to make full use of the port operations. Signed-off-by: Alan Cox <alan@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-01-02tty: make rocketport use standard port->flagsAlan Cox1-19/+19
We need to this ready for using the standard helpers Signed-off-by: Alan Cox <alan@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-01-02tty: Redo the rocket driver lockingAlan Cox1-17/+18
Bring this driver into the port locking model Signed-off-by: Alan Cox <alan@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-01-02tty: Remove some pointless castsAlan Cox1-18/+18
disc_data and driver_data are void * Signed-off-by: Alan Cox <alan@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-01-02tty: rocketport uses different port flags to everyone elseAlan Cox1-20/+20
Normalise them so we can use the common helpers later on Signed-off-by: Alan Cox <alan@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-01-02tty: Pull the dtr raise into tty portAlan Cox1-4/+10
This moves another per device special out of what should be shared open wait paths into private methods Signed-off-by: Alan Cox <alan@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-01-02tty_port: Add a port level carrier detect operationAlan Cox1-14/+26
This is the first step to generalising the various pieces of waiting logic duplicated in all sorts of serial drivers. Signed-off-by: Alan Cox <alan@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-22tty: rework break handlingAlan Cox1-2/+3
Some hardware needs to do break handling itself and may have partial support only. Make break_ctl return an error code. Add a tty driver flag so you can indicate driver hardware side break support. Signed-off-by: Alan Cox <alan@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-20tty: add more tty_port fieldsAlan Cox1-11/+12
Move more bits into the tty_port structure Signed-off-by: Alan Cox <alan@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-20rocket: use tty_portAlan Cox1-58/+58
Switch the rocketport to use the new tty_port structure Signed-off-by: Alan Cox <alan@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-30riscom/rocket: switch to int put_char methodAlan Cox1-2/+3
Signed-off-by: Alan Cox <alan@redhat.com> Cc: Jiri Slaby <jirislaby@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-30tty/serial: lay the foundations for the next set of reworksAlan Cox1-0/+2
- Stop drivers calling their own flush method indirectly, it obfuscates code and it will change soon anyway - A few more lock_kernel paths temporarily needed in some driver internal waiting code - Remove private put_char method that does a write call for one char - we have that anyway - Most but not yet all of the termios copy under lock fixing (some has other dependencies to follow) - Note a few locking bugs in drivers found in the process - Kill remaining [ab]users of TIOCG/SSOFTCAR in the driver, these must go to fix the termios locking Signed-off-by: Alan Cox <alan@redhat.com> Cc: Jiri Slaby <jirislaby@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-30char: rocket.c: fix sparse variable shadowing and int as NULL pointerHarvey Harrison1-4/+5
Nested min() macros shadow _x, separate into two lines. drivers/char/rocket.c:451:7: warning: symbol '_x' shadows an earlier one drivers/char/rocket.c:451:7: originally declared here drivers/char/rocket.c:451:7: warning: symbol '_x' shadows an earlier one drivers/char/rocket.c:451:7: originally declared here drivers/char/rocket.c:451:7: warning: symbol '_y' shadows an earlier one drivers/char/rocket.c:451:7: originally declared here drivers/char/rocket.c:1754:7: warning: symbol '_x' shadows an earlier one drivers/char/rocket.c:1754:7: originally declared here drivers/char/rocket.c:1754:7: warning: symbol '_x' shadows an earlier one drivers/char/rocket.c:1754:7: originally declared here drivers/char/rocket.c:1754:7: warning: symbol '_y' shadows an earlier one drivers/char/rocket.c:1754:7: originally declared here drivers/char/rocket.c:1751:20: warning: Using plain integer as NULL pointer Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-30rocket: Prepare for BKL pushdownAlan Cox1-9/+18
Wrap the ioctl code in lock_kernel calls Signed-off-by: Alan Cox <alan@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-03-19drivers/char/rocket portability fixesAl Viro1-18/+19
unsigned long != __le32, TYVM, and unsigned char[4] is not guaranteed to be aligned for u32. While we are at it, sanitize sOutDW() a bit - have it take Byte_t * and handle dereferencing internally. NB: sWriteTxPrioByte() is almost certainly buggered on big-endian and is missing cpu_to_le16() on assignments to *WordPtr; I've left it alone for now. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Acked-by: "Theodore Ts'o" <tytso@mit.edu> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-08rocket: don't let random users reset the controllerAlan Cox1-0/+3
Signed-off-by: Alan Cox <alan@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-08rocket: first pass at termios reportingAlan Cox1-10/+8
Also removes a cflag comparison that caused some mode changes to get wrongly ignored Signed-off-by: Alan Cox <alan@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-07Char: rocket, remove useless macrosJiri Slaby1-9/+2
Signed-off-by: Jiri Slaby <jirislaby@gmail.com> Acked-by: Alan Cox <alan@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-07Char: rocket, printk cleanupJiri Slaby1-41/+48
- add KERN_ level to each print - change some levels appropriately - add \n at the ends where missing - change two complex printks into dev_info, where the original info is printed automatically Signed-off-by: Jiri Slaby <jirislaby@gmail.com> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-07Char: rocket, switch long delay to sleepJiri Slaby1-4/+4
Don't busy wait for whole 1s when registering some rocket modems. Sleep instead since we are not in atomic. Signed-off-by: Jiri Slaby <jirislaby@gmail.com> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-19Fix misspellings of "system", "controller", "interrupt" and "necessary".Robert P. J. Day1-1/+1
Fix the various misspellings of "system", controller", "interrupt" and "[un]necessary". Signed-off-by: Robert P. J. Day <rpjday@mindspring.com> Signed-off-by: Adrian Bunk <bunk@kernel.org>
2007-10-18Char: rocket, fix signed/unsigned warningJiri Slaby1-2/+2
Signed-off-by: Jiri Slaby <jirislaby@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-18Char: rocket, remove potential leak in module_initJiri Slaby1-14/+20
if (controller && !request_region) then we leaked a tty driver struct, fix it by adding function deinit tail with goto-ing into it (and from other fail paths too) Signed-off-by: Jiri Slaby <jirislaby@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-18Char: rocket, remove pci_read_config_dword(CLASS_REVISION)Jiri Slaby1-11/+4
We may use pdev->revision instead of reading pci config space directly, so remove pci_read_config_dword invoking. Signed-off-by: Jiri Slaby <jirislaby@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-18Char: rocket, don't re-set statics to 0Jiri Slaby1-12/+0
Signed-off-by: Jiri Slaby <jirislaby@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-18Char: rocket, fix dynamic_dev ttyJiri Slaby1-5/+9
- register_device unconditionally (non-pci dependent) to have also isa devices in /dev - unregister devices on module removal - don't set TTY_DRIVER_DYNAMIC_DEV twice (removed the one dependent on some macro) Signed-off-by: Jiri Slaby <jirislaby@gmail.com> Cc: Ferenc Wagner <wferi@niif.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-18Char: rocket, switch sleep_on to completionJiri Slaby1-4/+8
rocket, switch sleep_on to completion - sleep_on is deprecated and racy, use completion instead - also check retval of interruptible function and return ERESTARTSYS eventually Signed-off-by: Jiri Slaby <jirislaby@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-19some kmalloc/memset ->kzalloc (tree wide)Yoann Padioleau1-2/+1
Transform some calls to kmalloc/memset to a single kzalloc (or kcalloc). Here is a short excerpt of the semantic patch performing this transformation: @@ type T2; expression x; identifier f,fld; expression E; expression E1,E2; expression e1,e2,e3,y; statement S; @@ x = - kmalloc + kzalloc (E1,E2) ... when != \(x->fld=E;\|y=f(...,x,...);\|f(...,x,...);\|x=E;\|while(...) S\|for(e1;e2;e3) S\) - memset((T2)x,0,E1); @@ expression E1,E2,E3; @@ - kzalloc(E1 * E2,E3) + kcalloc(E1,E2,E3) [akpm@linux-foundation.org: get kcalloc args the right way around] Signed-off-by: Yoann Padioleau <padator@wanadoo.fr> Cc: Richard Henderson <rth@twiddle.net> Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru> Acked-by: Russell King <rmk@arm.linux.org.uk> Cc: Bryan Wu <bryan.wu@analog.com> Acked-by: Jiri Slaby <jirislaby@gmail.com> Cc: Dave Airlie <airlied@linux.ie> Acked-by: Roland Dreier <rolandd@cisco.com> Cc: Jiri Kosina <jkosina@suse.cz> Acked-by: Dmitry Torokhov <dtor@mail.ru> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Acked-by: Mauro Carvalho Chehab <mchehab@infradead.org> Acked-by: Pierre Ossman <drzeus-list@drzeus.cx> Cc: Jeff Garzik <jeff@garzik.org> Cc: "David S. Miller" <davem@davemloft.net> Acked-by: Greg KH <greg@kroah.com> Cc: James Bottomley <James.Bottomley@steeleye.com> Cc: "Antonino A. Daplas" <adaplas@pol.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-16rocket.c: fix unchecked mutex_lock_interruptible()Satyam Sharma1-1/+2
Check the return of mutex_lock_interruptible() in drivers/char/rocket.c and return ERESTARTSYS if we were interrupted. Signed-off-by: Satyam Sharma <satyam.sharma@gmail.com> Cc: Jiri Slaby <jirislaby@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-11Kill unused sesssion and group values in rocket driverSukadev Bhattiprolu1-3/+0
The process_session() and process_group() values are not really used by the driver. Signed-off-by: Sukadev Bhattiprolu <sukadev@us.ibm.com> Cc: Cedric Le Goater <clg@fr.ibm.com> Cc: Dave Hansen <haveblue@us.ibm.com> Cc: Serge Hallyn <serue@us.ibm.com> Cc: <containers@lists.osdl.org> Cc: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-08use mutex instead of semaphore in RocketPort driverMatthias Kaehlcke1-8/+11
The RocketPort driver uses a semaphore as mutex. Use the mutex API instead of the (binary) semaphore. Signed-off-by: Matthias Kaehlcke <matthias.kaehlcke@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-08drivers/char: use __set_current_state()Milind Arun Choudhary1-2/+2
use __set_current_state(TASK_*) instead of current->state = TASK_*, Signed-off-by: Milind Arun Choudhary <milindchoudhary@gmail.com> Cc: Jiri Slaby <jirislaby@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-08Char: rocket, add MODULE_DEVICE_TABLEJiri Slaby1-0/+6
rocket, add MODULE_DEVICE_TABLE Signed-off-by: Jiri Slaby <jirislaby@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-08rocket: remove modversions includeRobert P. J. Day1-4/+0
It misspelled "MODVERSIONS" preprocessor variable with "CONFIG_MODVERSIONS". Just kill it all. Signed-off-by: Robert P. J. Day <rpjday@mindspring.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-02-12[PATCH] Char: timers cleanupJiri Slaby1-7/+3
- Use timer macros to set function and data members and to modify expiration time. - Use DEFINE_TIMER for global timers and do not init them at run-time in these cases. - del_timer_sync is common in most cases -- we want to wait for timer function if it's still running. Signed-off-by: Jiri Slaby <jirislaby@gmail.com> Cc: Dave Airlie <airlied@linux.ie> Cc: David Woodhouse <dwmw2@infradead.org> Cc: Dominik Brodowski <linux@dominikbrodowski.net> Cc: Alessandro Zummo <a.zummo@towertech.it> Cc: Paul Fulghum <paulkf@microgate.com> Cc: Kylene Jo Hall <kjhall@us.ibm.com> Cc: Wim Van Sebroeck <wim@iguana.be> Acked-by: Dmitry Torokhov <dtor@mail.ru> (Input bits) Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-02-11[PATCH] Char: tty_wakeup cleanupJiri Slaby1-3/+0
tty_wakeup cleanup - remove wake_up_interruptible(&tty->write_wait) surrounding tty_wakup(tty); - substitute tty->ldisc.write_wakeup(tty) + wake_up() by tty_wakeup(tty); Signed-off-by: Jiri Slaby <jirislaby@gmail.com> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Acked-by: Tilman Schmidt <tilman@imap.cc> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2006-12-08[PATCH] tty: switch to ktermiosAlan Cox1-3/+5
This is the grungy swap all the occurrences in the right places patch that goes with the updates. At this point we have the same functionality as before (except that sgttyb() returns speeds not zero) and are ready to begin turning new stuff on providing nobody reports lots of bugs If you are a tty driver author converting an out of tree driver the only impact should be termios->ktermios name changes for the speed/property setting functions from your upper layers. If you are implementing your own TCGETS function before then your driver was broken already and its about to get a whole lot more painful for you so please fix it 8) Also fill in c_ispeed/ospeed on init for most devices, although the current code will do this for you anyway but I'd like eventually to lose that extra paranoia [akpm@osdl.org: bluetooth fix] [mp3@de.ibm.com: sclp fix] [mp3@de.ibm.com: warning fix for tty3270] [hugh@veritas.com: fix tty_ioctl powerpc build] [jdike@addtoit.com: uml: fix ->set_termios declaration] Signed-off-by: Alan Cox <alan@redhat.com> Signed-off-by: Martin Peschke <mp3@de.ibm.com> Acked-by: Peter Oberparleiter <oberpar@de.ibm.com> Cc: Cornelia Huck <cornelia.huck@de.ibm.com> Signed-off-by: Hugh Dickins <hugh@veritas.com> Signed-off-by: Jeff Dike <jdike@addtoit.com> Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-08[PATCH] add process_session() helper routineCedric Le Goater1-1/+1
Replace occurences of task->signal->session by a new process_session() helper routine. It will be useful for pid namespaces to abstract the session pid number. Signed-off-by: Cedric Le Goater <clg@fr.ibm.com> Cc: Kirill Korotaev <dev@openvz.org> Cc: Eric W. Biederman <ebiederm@xmission.com> Cc: Herbert Poetzl <herbert@13thfloor.at> Cc: Sukadev Bhattiprolu <sukadev@us.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-02[PATCH] const struct tty_operationsJeff Dike1-1/+1
As part of an SMP cleanliness pass over UML, I consted a bunch of structures in order to not have to document their locking. One of these structures was a struct tty_operations. In order to const it in UML without introducing compiler complaints, the declaration of tty_set_operations needs to be changed, and then all of its callers need to be fixed. This patch declares all struct tty_operations in the tree as const. In all cases, they are static and used only as input to tty_set_operations. As an extra check, I ran an i386 allyesconfig build which produced no extra warnings. 53 drivers are affected. I checked the history of a bunch of them, and in most cases, there have been only a handful of maintenance changes in the last six months. serial_core.c was the busiest one that I looked at. Signed-off-by: Jeff Dike <jdike@addtoit.com> Acked-by: Alan Cox <alan@redhat.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-26[PATCH] devfs: Rename TTY_DRIVER_NO_DEVFS to TTY_DRIVER_DYNAMIC_DEVGreg Kroah-Hartman1-2/+2
I've always found this flag confusing. Now that devfs is no longer around, it has been renamed, and the documentation for when this flag should be used has been updated. Also fixes all drivers that use this flag. Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-06-26[PATCH] devfs: Remove the tty_driver devfs_name field as it's no longer neededGreg Kroah-Hartman1-1/+0
Also fixes all drivers that set this field. Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-06-25[PATCH] fix memory leak in rocketport rp_do_receivePaul Fulghum1-39/+23
Fix memory leak caused by incorrect use of tty buffer facility. tty buffers are allocated but never processed by call to tty_flip_buffer_push so they accumulate on the full buffer list. Current code uses the buffers as a temporary storage for data before passing it directly to the line discipline. Signed-off-by: Paul Fulghum <paulkf@microgate.com> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-02-03[PATCH] Fix RocketPort driverMichal Ostrowski1-1/+1
Call "ld->receive_buf" using the start of the character and flag buffers, rather than the ends. Signed-off-by: Michal Ostrowski <mostrows@watson.ibm.com> Acked-by: Alan Cox <alan@redhat.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-10[PATCH] TTY layer buffering revampAlan Cox1-9/+10
The API and code have been through various bits of initial review by serial driver people but they definitely need to live somewhere for a while so the unconverted drivers can get knocked into shape, existing drivers that have been updated can be better tuned and bugs whacked out. This replaces the tty flip buffers with kmalloc objects in rings. In the normal situation for an IRQ driven serial port at typical speeds the behaviour is pretty much the same, two buffers end up allocated and the kernel cycles between them as before. When there are delays or at high speed we now behave far better as the buffer pool can grow a bit rather than lose characters. This also means that we can operate at higher speeds reliably. For drivers that receive characters in blocks (DMA based, USB and especially virtualisation) the layer allows a lot of driver specific code that works around the tty layer with private secondary queues to be removed. The IBM folks need this sort of layer, the smart serial port people do, the virtualisers do (because a virtualised tty typically operates at infinite speed rather than emulating 9600 baud). Finally many drivers had invalid and unsafe attempts to avoid buffer overflows by directly invoking tty methods extracted out of the innards of work queue structs. These are no longer needed and all go away. That fixes various random hangs with serial ports on overflow. The other change in here is to optimise the receive_room path that is used by some callers. It turns out that only one ldisc uses receive room except asa constant and it updates it far far less than the value is read. We thus make it a variable not a function call. I expect the code to contain bugs due to the size alone but I'll be watching and squashing them and feeding out new patches as it goes. Because the buffers now dynamically expand you should only run out of buffering when the kernel runs out of memory for real. That means a lot of the horrible hacks high performance drivers used to do just aren't needed any more. Description: tty_insert_flip_char is an old API and continues to work as before, as does tty_flip_buffer_push() [this is why many drivers dont need modification]. It does now also return the number of chars inserted There are also tty_buffer_request_room(tty, len) which asks for a buffer block of the length requested and returns the space found. This improves efficiency with hardware that knows how much to transfer. and tty_insert_flip_string_flags(tty, str, flags, len) to insert a string of characters and flags For a smart interface the usual code is len = tty_request_buffer_room(tty, amount_hardware_says); tty_insert_flip_string(tty, buffer_from_card, len); More description! At the moment tty buffers are attached directly to the tty. This is causing a lot of the problems related to tty layer locking, also problems at high speed and also with bursty data (such as occurs in virtualised environments) I'm working on ripping out the flip buffers and replacing them with a pool of dynamically allocated buffers. This allows both for old style "byte I/O" devices and also helps virtualisation and smart devices where large blocks of data suddenely materialise and need storing. So far so good. Lots of drivers reference tty->flip.*. Several of them also call directly and unsafely into function pointers it provides. This will all break. Most drivers can use tty_insert_flip_char which can be kept as an API but others need more. At the moment I've added the following interfaces, if people think more will be needed now is a good time to say int tty_buffer_request_room(tty, size) Try and ensure at least size bytes are available, returns actual room (may be zero). At the moment it just uses the flipbuf space but that will change. Repeated calls without characters being added are not cumulative. (ie if you call it with 1, 1, 1, and then 4 you'll have four characters of space. The other functions will also try and grow buffers in future but this will be a more efficient way when you know block sizes. int tty_insert_flip_char(tty, ch, flag) As before insert a character if there is room. Now returns 1 for success, 0 for failure. int tty_insert_flip_string(tty, str, len) Insert a block of non error characters. Returns the number inserted. int tty_prepare_flip_string(tty, strptr, len) Adjust the buffer to allow len characters to be added. Returns a buffer pointer in strptr and the length available. This allows for hardware that needs to use functions like insl or mencpy_fromio. Signed-off-by: Alan Cox <alan@redhat.com> Cc: Paul Fulghum <paulkf@microgate.com> Signed-off-by: Hirokazu Takata <takata@linux-m32r.org> Signed-off-by: Serge Hallyn <serue@us.ibm.com> Signed-off-by: Jeff Dike <jdike@addtoit.com> Signed-off-by: John Hawkes <hawkes@sgi.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Adrian Bunk <bunk@stusta.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
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