scsi: mpt3sas: fix hang on ata passthrough commands
authorJames Bottomley <James.Bottomley@HansenPartnership.com>
Sun, 1 Jan 2017 17:39:24 +0000 (09:39 -0800)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Thu, 26 Jan 2017 07:24:44 +0000 (08:24 +0100)
commit16236802bfecb1082144a48b7d6fa60997824662
tree58b0862671f165f26107765f0560cbc11b9569d5
parenta07a122ad2a2e03209155fe907bf8b1e6ae4c915
scsi: mpt3sas: fix hang on ata passthrough commands

commit ffb58456589443ca572221fabbdef3db8483a779 upstream.

mpt3sas has a firmware failure where it can only handle one pass through
ATA command at a time.  If another comes in, contrary to the SAT
standard, it will hang until the first one completes (causing long
commands like secure erase to timeout).  The original fix was to block
the device when an ATA command came in, but this caused a regression
with

commit 669f044170d8933c3d66d231b69ea97cb8447338
Author: Bart Van Assche <bart.vanassche@sandisk.com>
Date:   Tue Nov 22 16:17:13 2016 -0800

    scsi: srp_transport: Move queuecommand() wait code to SCSI core

So fix the original fix of the secure erase timeout by properly
returning SAM_STAT_BUSY like the SAT recommends.  The original patch
also had a concurrency problem since scsih_qcmd is lockless at that
point (this is fixed by using atomic bitops to set and test the flag).

[mkp: addressed feedback wrt. test_bit and fixed whitespace]

Fixes: 18f6084a989ba1b (mpt3sas: Fix secure erase premature termination)
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
Acked-by: Sreekanth Reddy <Sreekanth.Reddy@broadcom.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reported-by: Ingo Molnar <mingo@kernel.org>
Tested-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
drivers/scsi/mpt3sas/mpt3sas_base.h
drivers/scsi/mpt3sas/mpt3sas_scsih.c