Bug#682233: (no subject)

[George Shuklin <george.shuklin@gmail.com>]

I think this commit is somehow related to that problem:

commit 14216561e164671ce147458653b1fea06a4ada1e
Author: James Bottomley <JBottomley@Parallels.com>
Date:   Wed Jul 25 23:55:55 2012 +0400

    [SCSI] Fix 'Device not ready' issue on mpt2sas

    This is a particularly nasty SCSI ATA Translation Layer (SATL) problem.

    SAT-2 says (section 8.12.2)

            if the device is in the stopped state as the result of
            processing a START STOP UNIT command (see 9.11), then the SATL
            shall terminate the TEST UNIT READY command with CHECK 
CONDITION
            status with the sense key set to NOT READY and the additional
            sense code of LOGICAL UNIT NOT READY, INITIALIZING COMMAND
            REQUIRED;

    mpt2sas internal SATL seems to implement this.  The result is very 
confusing
    standby behaviour (using hdparm -y).  If you suspend a drive and 
then send
    another command, usually it wakes up.  However, if the next command 
is a TEST
    UNIT READY, the SATL sees that the drive is suspended and proceeds 
to follow
    the SATL rules for this, returning NOT READY to all subsequent 
commands.  This
    means that the ordering of TEST UNIT READY is crucial: if you send 
TUR and
    then a command, you get a NOT READY to both back.  If you send a 
command and
    then a TUR, you get GOOD status because the preceeding command woke 
the drive.

    This bit us badly because