linux.git/drivers/scsi/sr.c, branch v3.17

scsi: move the writeable field from struct scsi_device to struct scsi_cd

2014-07-25T21:16:41+00:00

We currently set the field in common code based on the device type,
but then only use it in the cdrom driver which also overrides the
value previously set in the generic code.

Just leave this entirely to the CDROM driver to make everyones life
simpler.

Signed-off-by: Christoph Hellwig 
Reviewed-by: Hannes Reinecke 
Reviewed-by: Martin K. Petersen

scsi: set sc_data_direction in common code

2014-07-17T20:11:41+00:00

The data direction fiel in the SCSI command is derived only from the block
request structure.  Move setting it up into common code instead of
duplicating it in the ULDs.

Signed-off-by: Christoph Hellwig 
Reviewed-by: Martin K. Petersen 
Reviewed-by: Hannes Reinecke

scsi: restructure command initialization for TYPE_FS requests

2014-07-17T20:11:27+00:00

We should call the device handler prep_fn for all TYPE_FS requests,
not just simple read/write calls that are handled by the disk driver.

Restructure the common I/O code to call the prep_fn handler and zero
out the CDB, and just leave the call to scsi_init_io to the ULDs.

Signed-off-by: Christoph Hellwig 
Reviewed-by: Martin K. Petersen 
Reviewed-by: Hannes Reinecke

scsi: Implement sr_printk()

2014-07-17T20:07:39+00:00

Update the sr driver to use dev_printk() variants instead of
plain printk(); this will prefix logging messages with the
appropriate device.

Signed-off-by: Hannes Reinecke 
Reviewed-by: Martin K. Petersen 
Reviewed-by: Christoph Hellwig 
Signed-off-by: Christoph Hellwig

scsi: reintroduce scsi_driver.init_command

2014-05-19T10:35:09+00:00

Instead of letting the ULD play games with the prep_fn move back to
the model of a central prep_fn with a callback to the ULD.  This
already cleans up and shortens the code by itself, and will be required
to properly support blk-mq in the SCSI midlayer.

Signed-off-by: Christoph Hellwig 
Reviewed-by: Nicholas Bellinger 
Reviewed-by: Mike Christie 
Reviewed-by: Hannes Reinecke

[SCSI] sr: use block layer runtime PM

2013-12-16T18:57:51+00:00

Migrate sr to make use of block layer runtime PM. Accordingly, the
SCSI bus layer runtime PM callback is simplified as all SCSI drivers
implementing runtime PM now use the block layer's request-based
mechanism.

Note that due to the device will be polled by kernel at a constant
interval, if the autosuspend delay is set longer than the polling
interval then the device will never suspend.

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

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