]> git.karo-electronics.de Git - karo-tx-linux.git/commit
SCSI: sd: Update WRITE SAME heuristics
authorMartin K. Petersen <martin.petersen@oracle.com>
Fri, 7 Jun 2013 02:15:55 +0000 (22:15 -0400)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Thu, 25 Jul 2013 21:07:30 +0000 (14:07 -0700)
commit98dcc2946adbe4349ef1ef9b99873b912831edd4
tree2b4a51a862e10f4cedc54c36d779e9ccfe69f962
parent64ea2992a29aa0bdc4eaf457351b063caafb6655
SCSI: sd: Update WRITE SAME heuristics

commit 66c28f97120e8a621afd5aa7a31c4b85c547d33d upstream.

SATA drives located behind a SAS controller would incorrectly receive
WRITE SAME commands. Tweak the heuristics so that:

 - If REPORT SUPPORTED OPERATION CODES is provided we will use that to
   choose between WRITE SAME(16), WRITE SAME(10) and disabled. This also
   fixes an issue with the old code which would issue WRITE SAME(10)
   despite the command not being whitelisted in REPORT SUPPORTED
   OPERATION CODES.

 - If REPORT SUPPORTED OPERATION CODES is not provided we will fall back
   to WRITE SAME(10) unless the device has an ATA Information VPD page.
   The assumption is that a SATL which is smart enough to implement
   WRITE SAME would also provide REPORT SUPPORTED OPERATION CODES.

To facilitate the new heuristics scsi_report_opcode() has been modified
to so we can distinguish between "operation not supported" and "RSOC not
supported".

Reported-by: H. Peter Anvin <hpa@zytor.com>
Tested-by: Bernd Schubert <bernd.schubert@itwm.fraunhofer.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
drivers/scsi/scsi.c
drivers/scsi/sd.c
drivers/scsi/sd.h