linux-toradex.git/drivers/scsi/sr.c, branch v3.11

block_device_operations->release() should return void

2013-05-07T06:16:21+00:00

The value passed is 0 in all but "it can never happen" cases (and those
only in a couple of drivers) *and* it would've been lost on the way
out anyway, even if something tried to pass something meaningful.
Just don't bother.

Signed-off-by: Al Viro

[libata] scsi: no poll when ODD is powered off

2013-01-25T20:36:43+00:00

When the ODD is powered off, any action the user did to the ODD that
would generate a media event will trigger an ACPI interrupt, so the
poll for media event is no longer necessary. And the poll will also
cause a runtime status change, which will stop the ODD from staying in
powered off state, so the poll should better be stopped.

But since we don't have access to the gendisk structure in LLDs, here
comes the disk_events_disable_depth for scsi device. This field is a
hint set by LLDs to convey information to upper layer drivers. A value
of 0 means media poll is necessary for the device, while values above 0
means media poll is not needed and should better be skipped. So we can
increase its value when we are to power off the ODD in ATA layer and
decrease its value when the ODD is powered on, effectively silence the
media events poll.

Signed-off-by: Aaron Lu 
Signed-off-by: Jeff Garzik

[SCSI] sr: support runtime pm

2013-01-25T20:36:38+00:00

This patch adds runtime pm support for sr.

It did this by increasing the runtime usage_count of the device when
its block device is accessed. And decreasing the runtime usage_count
of the device when the access is done.

If there is media inside, runtime suspend is not allowed as we don't
always know if the ODD is being used or not.

The idea is discussed here:
http://thread.gmane.org/gmane.linux.acpi.devel/55243/focus=52703
and the restriction to check media inside is discussed here:
http://thread.gmane.org/gmane.linux.ide/53665/focus=58836

Signed-off-by: Aaron Lu 
Acked-by: Alan Stern 
Acked-by: James Bottomley 
Signed-off-by: Jeff Garzik

[SCSI] sr: check_events() ignore GET_EVENT when TUR says otherwise

2011-07-21T21:15:58+00:00

Some broken devices indicates that media has changed on every
GET_EVENT_STATUS_NOTIFICATION.  This translates into MEDIA_CHANGE
uevent on every open() which lets udev run into a loop.

Verify GET_EVENT result against TUR and if it generates spurious
events for several times in a row, ignore the GET_EVENT events, and
trust only the TUR status.

This is the log of a USB stick with a (broken) fake CDROM drive:

 scsi 5:0:0:0: Direct-Access     SanDisk  U3 Cruzer Micro  8.02 PQ: 0 ANSI: 0 CCS
 sd 5:0:0:0: Attached scsi generic sg3 type 0
 scsi 5:0:0:1: CD-ROM            SanDisk  U3 Cruzer Micro  8.02 PQ: 0 ANSI: 0
 sd 5:0:0:0: [sdb] Attached SCSI removable disk
 sr2: scsi3-mmc drive: 48x/48x tray
 sr 5:0:0:1: Attached scsi CD-ROM sr2
 sr 5:0:0:1: Attached scsi generic sg4 type 5
 sr2: GET_EVENT and TUR disagree continuously, suppress GET_EVENT events
 sd 5:0:0:0: [sdb] 31777279 512-byte logical blocks: (16.2 GB/15.1 GiB)
 sd 5:0:0:0: [sdb] No Caching mode page present
 sd 5:0:0:0: [sdb] Assuming drive cache: write through
 sd 5:0:0:0: [sdb] No Caching mode page present
 sd 5:0:0:0: [sdb] Assuming drive cache: write through
 sdb: sdb1

-tj: Updated to consider only spurious GET_EVENT events among
     different types of disagreement and allow using TUR for kernel
     event polling after GET_EVENT is ignored.

Reported-By: Markus Rathgeb maggu2810@googlemail.com
Signed-off-by: Kay Sievers 
Signed-off-by: Tejun Heo 
Cc: stable@kernel.org	# >= v2.6.38, fixes udev busy looping w/ certain devices
Signed-off-by: James Bottomley

block: don't block events on excl write for non-optical devices

2011-04-21T18:54:46+00:00

Disk event code automatically blocks events on excl write.  This is
primarily to avoid issuing polling commands while burning is in
progress.  This behavior doesn't fit other types of devices with
removeable media where polling commands don't have adverse side
effects and door locking usually doesn't exist.

This patch introduces new genhd flag which controls the auto-blocking
behavior and uses it to enable auto-blocking only on optical devices.

Note for stable: 2.6.38 and later only

Cc: stable@kernel.org
Signed-off-by: Tejun Heo 
Reported-by: Kay Sievers 
Signed-off-by: Jens Axboe

Fix common misspellings

2011-03-31T14:26:23+00:00

Fixes generated by 'codespell' and manually reviewed.

Signed-off-by: Lucas De Marchi

[SCSI] sd,sr: kill compat SDEV_MEDIA_CHANGE event

2011-01-14T15:17:35+00:00

SDEV_MEDIA_CHANGE event was first added by commit a341cd0f (SCSI: add
asynchronous event notification API) for SATA AN support and then
extended to cover generic media change events by commit 285e9670
([SCSI] sr,sd: send media state change modification events).

This event was mapped to block device in userland with all properties
stripped to simulate CHANGE event on the block device, which, in turn,
was used to trigger further userspace action on media change.

The recent addition of disk event framework kept this event for
backward compatibility but it turns out to be unnecessary and causes
erratic and inefficient behavior.  The new disk event generates proper
events on the block devices and the compat events are mapped to block
device with all properties stripped, so the block device ends up
generating multiple duplicate events for single actual event.

This patch removes the compat event generation from both sr and sd as
suggested by Kay Sievers.  Both existing and newer versions of udev
and the associated tools will behave better with the removal of these
events as they from the beginning were expecting events on the block
devices.

Signed-off-by: Tejun Heo 
Acked-by: Kay Sievers 
Signed-off-by: James Bottomley

sr: implement sr_check_events()

2010-12-16T16:53:39+00:00

Replace sr_media_change() with sr_check_events().  It normally only
uses GET_EVENT_STATUS_NOTIFICATION to check both media change and
eject request.  If @clearing includes DISK_EVENT_MEDIA_CHANGE, it
issues TUR and compares whether media presence has changed.  The SCSI
specific media change uevent is kept for compatibility.

sr_media_change() was doing both media change check and revalidation.
The revalidation part is split into sr_block_revalidate_disk().

Signed-off-by: Tejun Heo 
Cc: Kay Sievers 
Signed-off-by: Jens Axboe

scsi: replace sr_test_unit_ready() with scsi_test_unit_ready()

2010-12-16T16:53:39+00:00

The usage of TUR has been confusing involving several different
commits updating different parts over time.  Currently, the only
differences between scsi_test_unit_ready() and sr_test_unit_ready()
are,

* scsi_test_unit_ready() also sets sdev->changed on NOT_READY.

* scsi_test_unit_ready() returns 0 if TUR ended with UNIT_ATTENTION or
  NOT_READY.

Due to the above two differences, sr is using its own
sr_test_unit_ready(), but sd - the sole user of the above extra
handling - doesn't even need them.

Where scsi_test_unit_ready() is used in sd_media_changed(), the code
is looking for device ready w/ media present state which is true iff
TUR succeeds w/o sense data or UA, and when the device is not ready
for whatever reason sd_media_changed() explicitly marks media as
missing so there's no reason to set sdev->changed automatically from
scsi_test_unit_ready() on NOT_READY.

Drop both special handlings from scsi_test_unit_ready(), which makes
it equivalant to sr_test_unit_ready(), and replace
sr_test_unit_ready() with scsi_test_unit_ready().  Also, drop the
unnecessary explicit NOT_READY check from sd_media_changed().
Checking return value is enough for testing device readiness.

Signed-off-by: Tejun Heo 
Signed-off-by: Jens Axboe

scsi: fix TUR error handling in sr_media_change()

2010-12-16T16:53:39+00:00

sr_test_unit_ready() returns 0 iff TUR succeeded - IOW, when media is
present and the device is actually ready, so the return value wouldn't
be zero when TUR ends with sense data. sr_media_change() incorrectly
tests (retval || (scsi_sense_valid(sshdr)...)) when it tries to test
whether TUR failed without sense data or with sense data indicating
media-not-present.

Fix the test using scsi_status_is_good() and update comments.

- Fixed a comment typo spotted by Eike.

Signed-off-by: Tejun Heo 
Cc: Rolf Eike Beer 
Signed-off-by: Jens Axboe