Hello, James. On Wed, Jul 25, 2012 at 06:19:13PM +0400, James Bottomley wrote: > > I haven't consulted SAT but it seems like a bug in SAS driver or > > firmware. If it's a driver bug, we better fix it there. If a > > firmware bug, working around those is one of major roles of drivers, > > so I think setting allow_restart is fine. > > Actually, I don't think so. SAT-2 section 8.12.2 does say > > 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; > > START STOP UNIT (with START=0) translates to STANDBY IMMEDIATE, and > that's what hdparm -y issues. We don't see this in /drivers/ata because > TEST UNIT READY always returns success.
Urgh... ATA device in standby mode is ready for any command and definitely doesn't need an "initializing command". Oh, well... > So it looks like the mpt2sas SAT is doing the correct thing and we only > don't see this problem in normal SATA devices because of a bug in the > libata-scsi SAT. libata is inconsistent with the standard but I think the standard is wrong here. :( Thanks. -- tejun -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
