linux-toradex.git/drivers/block/cciss_scsi.c, branch v3.3-rc4

cciss: auto engage SCSI mid layer at driver load time

2011-11-16T08:21:49+00:00

A long time ago, probably in 2002, one of the distros, or maybe more than
one, loaded block drivers prior to loading the SCSI mid layer.  This meant
that the cciss driver, being a block driver, could not engage the SCSI mid
layer at init time without panicking, and relied on being poked by a
userland program after the system was up (and the SCSI mid layer was
therefore present) to engage the SCSI mid layer.

This is no longer the case, and cciss can safely rely on the SCSI mid
layer being present at init time and engage the SCSI mid layer straight
away.  This means that users will see their tape drives and medium
changers at driver load time without need for a script in /etc/rc.d that
does this:

for x in /proc/driver/cciss/cciss*
do
	echo "engage scsi" > $x
done

However, if no tape drives or medium changers are detected, the SCSI mid
layer will not be engaged.  If a tape drive or medium change is later
hot-added to the system it will then be necessary to use the above script
or similar for the device(s) to be acceesible.

Signed-off-by: Stephen M. Cameron 
Signed-off-by: Andrew Morton 
Signed-off-by: Jens Axboe

atomic: use

2011-07-26T23:49:47+00:00

This allows us to move duplicated code in 
(atomic_inc_not_zero() for now) to 

Signed-off-by: Arun Sharma 
Reviewed-by: Eric Dumazet 
Cc: Ingo Molnar 
Cc: David Miller 
Cc: Eric Dumazet 
Acked-by: Mike Frysinger 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

cciss: add cciss_tape_cmds module paramter

2011-05-06T14:23:59+00:00

This is to allow number of commands reserved for use by SCSI tape drives
and medium changers to be adjusted at driver load time via the kernel
parameter cciss_tape_cmds, with a default value of 6, and a range
of 2 - 16 inclusive.  Previously, the driver limited the number of
commands which could be queued to the SCSI half of the the driver
to only 2.  This is to fix the problem that if you had more than
two tape drives, you couldn't, for example, erase or rewind them all
at the same time.

Signed-off-by: Stephen M. Cameron 
Signed-off-by: Jens Axboe

Revert "cciss: Add missing allocation in scsi_cmd_stack_setup and corresponding deallocation"

2011-03-12T12:47:51+00:00

This reverts commit 978eb516a4e1a1b47163518d6f5d5e81ab27a583.

The commit was broken, relying on other changes that have not been
committed yet.

Signed-off-by: Jens Axboe

cciss: fix missed command status value CMD_UNABORTABLE

2011-03-12T09:02:30+00:00

and fix a nearby typo, "do" that should have been "due"

Signed-off-by: Stephen M. Cameron 
Signed-off-by: Jens Axboe

cciss: Add missing allocation in scsi_cmd_stack_setup and corresponding deallocation

2011-03-11T19:07:38+00:00

This bit got lost somewhere along the way.  Without this, panic.

Signed-off-by: Stephen M. Cameron 
Cc: stable@kernel.org
Signed-off-by: Jens Axboe

SCSI host lock push-down

2010-11-16T21:33:23+00:00

Move the mid-layer's ->queuecommand() invocation from being locked
with the host lock to being unlocked to facilitate speeding up the
critical path for drivers who don't need this lock taken anyway.

The patch below presents a simple SCSI host lock push-down as an
equivalent transformation.  No locking or other behavior should change
with this patch.  All existing bugs and locking orders are preserved.

Additionally, add one parameter to queuecommand,
	struct Scsi_Host *
and remove one parameter from queuecommand,
	void (*done)(struct scsi_cmnd *)

Scsi_Host* is a convenient pointer that most host drivers need anyway,
and 'done' is redundant to struct scsi_cmnd->scsi_done.

Minimal code disturbance was attempted with this change.  Most drivers
needed only two one-line modifications for their host lock push-down.

Signed-off-by: Jeff Garzik 
Acked-by: James Bottomley 
Signed-off-by: Linus Torvalds

cciss: change printks to dev_warn, etc.

2010-08-07T16:52:30+00:00

cciss: change printks to dev_warn, etc.

Signed-off-by: Stephen M. Cameron 
Signed-off-by: Jens Axboe

cciss: separate cmd_alloc() and cmd_special_alloc()

2010-08-07T16:52:30+00:00

cciss: separate cmd_alloc() and cmd_special_alloc()
cmd_alloc() took a parameter which caused it to either allocate
from a pre-allocated pool, or allocate using pci_alloc_consistent.
This parameter is always known at compile time, so this would
be better handled by breaking the function into two functions
and differentiating the cases by function names.  Same goes
for cmd_free().

Signed-off-by: Stephen M. Cameron 
Signed-off-by: Jens Axboe

cciss: use consistent variable names

2010-08-07T16:52:30+00:00

cciss: use consistent variable names
"h", for the hba structure and "c" for the command structures.
and get rid of trivial CCISS_LOCK macro.

Signed-off-by: Stephen M. Cameron 
Signed-off-by: Jens Axboe