A-Team_Digital_Solutions/android_kernel_motorola_sm6375
Watch
2
0
Fork
You've already forked android_kernel_motorola_sm6375
 0
mirror of https://github.com/BobTheBlinker/android_kernel_motorola_sm6375.git synced 2026-10-29 03:01:39 -04:00
Code Issues Projects Releases Packages Wiki Activity

SCSI & usb-storage: add try_rc_10_first flag

Browse source 
Several bug reports have been received recently for USB mass-storage
devices that don't handle READ CAPACITY(16) commands properly.  They
report bogus sizes, in some cases becoming unusable as a result.

The bugs were triggered by commit
09b6b51b0b (SCSI & usb-storage: add
flags for VPD pages and REPORT LUNS), which caused usb-storage to stop
overriding the SCSI level reported by devices.  By default, the sd
driver will try READ CAPACITY(16) first for any device whose level is
above SCSI_SPC_2.

It seems likely that any device large enough to require the use of
READ CAPACITY(16) (i.e., 2 TB or more) would be able to handle READ
CAPACITY(10) commands properly.  Indeed, I don't know of any devices
that don't handle READ CAPACITY(10) properly.

Therefore this patch (as1559) adds a new flag telling the sd driver
to try READ CAPACITY(10) before READ CAPACITY(16), and sets this flag
for every USB mass-storage device.  If a device really is larger than
2 TB, sd will fall back to READ CAPACITY(16) just as it used to.

This fixes Bugzilla #43391.

Signed-off-by: Alan Stern <[email protected]>
Acked-by: Hans de Goede <[email protected]>
CC: "James E.J. Bottomley" <[email protected]>
CC: Matthew Dharm <[email protected]>
Cc: stable <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
This commit is contained in:
Alan Stern 2012-06-20 16:04:19 -04:00 • committed by Greg Kroah-Hartman
commit 6a0bdffa00
3 changed files with 9 additions and 0 deletions
Download patch file Download diff file Expand all files Collapse all files

6
drivers/usb/storage/scsiglue.c
View file

@ -202,6 +202,12 @@ static int slave_configure(struct scsi_device *sdev)
if (us->fflags & US_FL_NO_READ_CAPACITY_16)
sdev->no_read_capacity_16 = 1;
/*
* Many devices do not respond properly to READ_CAPACITY_16.
* Tell the SCSI layer to try READ_CAPACITY_10 first.
*/
sdev->try_rc_10_first = 1;
/* assume SPC3 or latter devices support sense size > 18 */
if (sdev->scsi_level > SCSI_SPC_2)
us->fflags |= US_FL_SANE_SENSE;