linux-toradex.git/drivers/firewire/sbp2.c, branch v3.10.78

firewire: don't use PREPARE_DELAYED_WORK

2014-03-24T04:38:16+00:00

commit 70044d71d31d6973665ced5be04ef39ac1c09a48 upstream.

PREPARE_[DELAYED_]WORK() are being phased out.  They have few users
and a nasty surprise in terms of reentrancy guarantee as workqueue
considers work items to be different if they don't have the same work
function.

firewire core-device and sbp2 have been been multiplexing work items
with multiple work functions.  Introduce fw_device_workfn() and
sbp2_lu_workfn() which invoke fw_device->workfn and
sbp2_logical_unit->workfn respectively and always use the two
functions as the work functions and update the users to set the
->workfn fields instead of overriding work functions using
PREPARE_DELAYED_WORK().

This fixes a variety of possible regressions since a2c1c57be8d9
"workqueue: consider work function when searching for busy work items"
due to which fw_workqueue lost its required non-reentrancy property.

Signed-off-by: Tejun Heo 
Acked-by: Stefan Richter 
Cc: linux1394-devel@lists.sourceforge.net
Signed-off-by: Greg Kroah-Hartman

firewire: sbp2: bring back WRITE SAME support

2014-01-09T20:24:21+00:00

commit ce027ed98fd176710fb14be9d6015697b62436f0 upstream.

Commit 54b2b50c20a6 "[SCSI] Disable WRITE SAME for RAID and virtual
host adapter drivers" disabled WRITE SAME support for all SBP-2 attached
targets.  But as described in the changelog of commit b0ea5f19d3d8
"firewire: sbp2: allow WRITE SAME and REPORT SUPPORTED OPERATION CODES",
it is not required to blacklist WRITE SAME.

Bring the feature back by reverting the sbp2.c hunk of commit 54b2b50c20a6.

Signed-off-by: Stefan Richter 
Signed-off-by: Greg Kroah-Hartman

SCSI: Disable WRITE SAME for RAID and virtual host adapter drivers

2013-12-12T06:36:28+00:00

commit 54b2b50c20a61b51199bedb6e5d2f8ec2568fb43 upstream.

Some host adapters do not pass commands through to the target disk
directly. Instead they provide an emulated target which may or may not
accurately report its capabilities. In some cases the physical device
characteristics are reported even when the host adapter is processing
commands on the device's behalf. This can lead to adapter firmware hangs
or excessive I/O errors.

This patch disables WRITE SAME for devices connected to host adapters
that provide an emulated target. Driver writers can disable WRITE SAME
by setting the no_write_same flag in the host adapter template.

[jejb: fix up rejections due to eh_deadline patch]
Signed-off-by: Martin K. Petersen 
Signed-off-by: James Bottomley 
Signed-off-by: Greg Kroah-Hartman

firewire: remove unnecessary alloc/OOM messages

2013-04-28T21:36:44+00:00

These are redundant to log messages from the mm core.

Signed-off-by: Stefan Richter

firewire: sbp2: replace BUG_ON by WARN_ON

2013-04-28T21:36:44+00:00

No need to crash and burn if S/G element sizes cannot be set to our
liking; just leave a message in the log.

Signed-off-by: Stefan Richter

firewire: Remove two unneeded checks for macros

2013-04-28T21:36:43+00:00

The old IEEE 1394 driver stack was removed in v2.6.37. That made the
checks for two Kconfig (module) macros unneeded, since they will now
always evaluate to true. Remove these two checks.

Signed-off-by: Paul Bolle 
Signed-off-by: Stefan Richter

firewire: sbp2: allow WRITE SAME and REPORT SUPPORTED OPERATION CODES

2012-12-02T19:10:18+00:00

The commits
    3c6bdaeab4fd "[SCSI] Add a report opcode helper"
    5db44863b6eb "[SCSI] sd: Implement support for WRITE SAME"
introduced in-kernel uses of the mentioned commands but cautiously
blacklisted them for any IEEE 1394 (SBP-2/3) targets and some other
transports.

I looked through a range of SBP devices and found that the blacklist
flags can be removed:

The kernel never attempts these commands if the device's INQUIRY
data claim a SCSI revision of less than 0x05.  This is the case with
all SBP devices that I checked, except for three more recent devices
which claimed a revision of 0x05 i.e. conformance with SPC-3 (two
devices based on the OXUF936QSE chip but having different firmwares,
one based on OXUF934DSB.)

I tried "sg_opcodes" from sg3_utils on several older and newer devices
and did not encounter any apparent firmware bugs with it.  All devices
returned Illegal Request/ Invalid command operation code and carried on.
I furthermore tried "sg_write_same -U" on the OXUF934DSB device with the
same result.  Alas I did not have a TRIM enabled SSD available for these
tests.  All of the bridges were correctly identified by the kernel as
"fully provisioned", CD-ROM devices aside.

The kernel won't issue WRITE SAME to fully provisioned devices, nor
would it attempt REPORT SUPPORTED OPERATION CODES or WRITE SAME with
UNMAP bit on devices which do not claim conformance to SPC-3 or later.

Hence let's remove the no_report_opcodes and no_write_same blacklist
flags so that these commands can be used on newer targets with
respective capabilities.  I guess the Linux sbp-target could be such a
target.

Signed-off-by: Stefan Richter

[SCSI] sd: Implement support for WRITE SAME

2012-11-14T06:45:42+00:00

Implement support for WRITE SAME(10) and WRITE SAME(16) in the SCSI disk
driver.

 - We set the default maximum to 0xFFFF because there are several
   devices out there that only support two-byte block counts even with
   WRITE SAME(16). We only enable transfers bigger than 0xFFFF if the
   device explicitly reports MAXIMUM WRITE SAME LENGTH in the BLOCK
   LIMITS VPD.

 - max_write_same_blocks can be overriden per-device basis in sysfs.

 - The UNMAP discovery heuristics remain unchanged but the discard
   limits are tweaked to match the "real" WRITE SAME commands.

 - In the error handling logic we now distinguish between WRITE SAME
   with and without UNMAP set.

The discovery process heuristics are:

 - If the device reports a SCSI level of SPC-3 or greater we'll issue
   READ SUPPORTED OPERATION CODES to find out whether WRITE SAME(16) is
   supported. If that's the case we will use it.

 - If the device supports the block limits VPD and reports a MAXIMUM
   WRITE SAME LENGTH bigger than 0xFFFF we will use WRITE SAME(16).

 - Otherwise we will use WRITE SAME(10) unless the target LBA is beyond
   0xFFFFFFFF or the block count exceeds 0xFFFF.

 - no_write_same is set for ATA, FireWire and USB.

Signed-off-by: Martin K. Petersen 
Reviewed-by: Mike Snitzer 
Reviewed-by: Jeff Garzik 
Signed-off-by: James Bottomley

[SCSI] Add a report opcode helper

2012-11-14T05:11:31+00:00

The REPORT SUPPORTED OPERATION CODES command can be used to query
whether a given opcode is supported by a device. Add a helper function
that allows us to look up commands.

We only issue RSOC if the device reports compliance with SPC-3 or
later. But to err on the side of caution we disable the command for ATA,
FireWire and USB.

Signed-off-by: Martin K. Petersen 
Acked-by: Mike Snitzer 
Signed-off-by: James Bottomley

firewire: sbp2: document the absence of alignment requirements

2012-05-21T19:49:44+00:00

The SBP-2/3 specifications do not require any alignment of data
buffers; only their own data structures need to be quadlet-aligned
[SR: or octlet-aligned].

Fix the comments to reflect this, but leave the actual alignment at
32 bits to avoid theoretical problems with target implementations
that might handle this incorrectly.

Signed-off-by: Clemens Ladisch 
Signed-off-by: Stefan Richter