Merge tag 'scsi-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi

Pull SCSI updates from James Bottomley:
 "This series has a huge amount of churn because it pulls in Mauro's doc
  update changing all our txt files to rst ones.

  Excluding that, we have the usual driver updates (qla2xxx, ufs, lpfc,
  zfcp, ibmvfc, pm80xx, aacraid), a treewide update for scnprintf and
  some other minor updates.

  The major core change is Hannes moving functions out of the aacraid
  driver and into the core"

* tag 'scsi-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi: (223 commits)
  scsi: aic7xxx: aic97xx: Remove FreeBSD-specific code
  scsi: ufs: Do not rely on prefetched data
  scsi: dc395x: remove dc395x_bios_param
  scsi: libiscsi: Fix error count for active session
  scsi: hpsa: correct race condition in offload enabled
  scsi: message: fusion: Replace zero-length array with flexible-array member
  scsi: qedi: Add PCI shutdown handler support
  scsi: qedi: Add MFW error recovery process
  scsi: ufs: Enable block layer runtime PM for well-known logical units
  scsi: ufs-qcom: Override devfreq parameters
  scsi: ufshcd: Let vendor override devfreq parameters
  scsi: ufshcd: Update the set frequency to devfreq
  scsi: ufs: Resume ufs host before accessing ufs device
  scsi: ufs-mediatek: customize the delay for enabling host
  scsi: ufs: make HCE polling more compact to improve initialization latency
  scsi: ufs: allow custom delay prior to host enabling
  scsi: ufs-mediatek: use common delay function
  scsi: ufs: introduce common and flexible delay function
  scsi: ufs: use an enum for host capabilities
  scsi: ufs: fix uninitialized tx_lanes in ufshcd_disable_tx_lcc()
  ...

1 files changed, 184 insertions, 0 deletions

diff --git a/Documentation/scsi/scsi-changer.rst b/Documentation/scsi/scsi-changer.rst
new file mode 100644
index 000000000000..ab60e7e61a6c
--- /dev/null
+++ b/Documentation/scsi/scsi-changer.rst
@@ -0,0 +1,184 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+========================================
+README for the SCSI media changer driver
+========================================
+
+This is a driver for SCSI Medium Changer devices, which are listed
+with "Type: Medium Changer" in /proc/scsi/scsi.
+
+This is for *real* Jukeboxes.  It is *not* supported to work with
+common small CD-ROM changers, neither one-lun-per-slot SCSI changers
+nor IDE drives.
+
+Userland tools available from here:
+	http://linux.bytesex.org/misc/changer.html
+
+
+General Information
+-------------------
+
+First some words about how changers work: A changer has 2 (possibly
+more) SCSI ID's. One for the changer device which controls the robot,
+and one for the device which actually reads and writes the data. The
+later may be anything, a MOD, a CD-ROM, a tape or whatever. For the
+changer device this is a "don't care", he *only* shuffles around the
+media, nothing else.
+
+
+The SCSI changer model is complex, compared to - for example - IDE-CD
+changers. But it allows to handle nearly all possible cases. It knows
+4 different types of changer elements:
+
+  ===============   ==================================================
+  media transport   this one shuffles around the media, i.e. the
+                    transport arm.  Also known as "picker".
+  storage           a slot which can hold a media.
+  import/export     the same as above, but is accessible from outside,
+                    i.e. there the operator (you !) can use this to
+                    fill in and remove media from the changer.
+		    Sometimes named "mailslot".
+  data transfer     this is the device which reads/writes, i.e. the
+		    CD-ROM / Tape / whatever drive.
+  ===============   ==================================================
+
+None of these is limited to one: A huge Jukebox could have slots for
+123 CD-ROM's, 5 CD-ROM readers (and therefore 6 SCSI ID's: the changer
+and each CD-ROM) and 2 transport arms. No problem to handle.
+
+
+How it is implemented
+---------------------
+
+I implemented the driver as character device driver with a NetBSD-like
+ioctl interface. Just grabbed NetBSD's header file and one of the
+other linux SCSI device drivers as starting point. The interface
+should be source code compatible with NetBSD. So if there is any
+software (anybody knows ???) which supports a BSDish changer driver,
+it should work with this driver too.
+
+Over time a few more ioctls where added, volume tag support for example
+wasn't covered by the NetBSD ioctl API.
+
+
+Current State
+-------------
+
+Support for more than one transport arm is not implemented yet (and
+nobody asked for it so far...).
+
+I test and use the driver myself with a 35 slot cdrom jukebox from
+Grundig.  I got some reports telling it works ok with tape autoloaders
+(Exabyte, HP and DEC).  Some People use this driver with amanda.  It
+works fine with small (11 slots) and a huge (4 MOs, 88 slots)
+magneto-optical Jukebox.  Probably with lots of other changers too, most
+(but not all :-) people mail me only if it does *not* work...
+
+I don't have any device lists, neither black-list nor white-list.  Thus
+it is quite useless to ask me whenever a specific device is supported or
+not.  In theory every changer device which supports the SCSI-2 media
+changer command set should work out-of-the-box with this driver.  If it
+doesn't, it is a bug.  Either within the driver or within the firmware
+of the changer device.
+
+
+Using it
+--------
+
+This is a character device with major number is 86, so use
+"mknod /dev/sch0 c 86 0" to create the special file for the driver.
+
+If the module finds the changer, it prints some messages about the
+device [ try "dmesg" if you don't see anything ] and should show up in
+/proc/devices. If not....  some changers use ID ? / LUN 0 for the
+device and ID ? / LUN 1 for the robot mechanism. But Linux does *not*
+look for LUNs other than 0 as default, because there are too many
+broken devices. So you can try:
+
+  1) echo "scsi add-single-device 0 0 ID 1" > /proc/scsi/scsi
+     (replace ID with the SCSI-ID of the device)
+  2) boot the kernel with "max_scsi_luns=1" on the command line
+     (append="max_scsi_luns=1" in lilo.conf should do the trick)
+
+
+Trouble?
+--------
+
+If you insmod the driver with "insmod debug=1", it will be verbose and
+prints a lot of stuff to the syslog.  Compiling the kernel with
+CONFIG_SCSI_CONSTANTS=y improves the quality of the error messages a lot
+because the kernel will translate the error codes into human-readable
+strings then.
+
+You can display these messages with the dmesg command (or check the
+logfiles).  If you email me some question because of a problem with the
+driver, please include these messages.
+
+
+Insmod options
+--------------
+
+debug=0/1
+	Enable debug messages (see above, default: 0).
+
+verbose=0/1
+	Be verbose (default: 1).
+
+init=0/1
+	Send INITIALIZE ELEMENT STATUS command to the changer
+	at insmod time (default: 1).
+
+timeout_init=<seconds>
+	timeout for the INITIALIZE ELEMENT STATUS command
+	(default: 3600).
+
+timeout_move=<seconds>
+	timeout for all other commands (default: 120).
+
+dt_id=<id1>,<id2>,... / dt_lun=<lun1>,<lun2>,...
+	These two allow to specify the SCSI ID and LUN for the data
+	transfer elements.  You likely don't need this as the jukebox
+	should provide this information.  But some devices don't ...
+
+vendor_firsts=, vendor_counts=, vendor_labels=
+	These insmod options can be used to tell the driver that there
+	are some vendor-specific element types.  Grundig for example
+	does this.  Some jukeboxes have a printer to label fresh burned
+	CDs, which is addressed as element 0xc000 (type 5).  To tell the
+	driver about this vendor-specific element, use this::
+
+		$ insmod ch			\
+			vendor_firsts=0xc000	\
+			vendor_counts=1		\
+			vendor_labels=printer
+
+	All three insmod options accept up to four comma-separated
+	values, this way you can configure the element types 5-8.
+	You likely need the SCSI specs for the device in question to
+	find the correct values as they are not covered by the SCSI-2
+	standard.
+
+
+Credits
+-------
+
+I wrote this driver using the famous mailing-patches-around-the-world
+method.  With (more or less) help from:
+
+	- Daniel Moehwald <moehwald@hdg.de>
+	- Dane Jasper <dane@sonic.net>
+	- R. Scott Bailey <sbailey@dsddi.eds.com>
+	- Jonathan Corbet <corbet@lwn.net>
+
+Special thanks go to
+
+	- Martin Kuehne <martin.kuehne@bnbt.de>
+
+for a old, second-hand (but full functional) cdrom jukebox which I use
+to develop/test driver and tools now.
+
+Have fun,
+
+   Gerd
+
+Gerd Knorr <kraxel@bytesex.org>