kernel/linux.git/include/linux/libata.h, branch v3.15.2

libata/ahci: accommodate tag ordered controllers

2014-04-18T19:56:03+00:00

The AHCI spec allows implementations to issue commands in tag order rather than FIFO order: 5.3.2.12 P:SelectCmd HBA sets pSlotLoc = (pSlotLoc + 1) mod (CAP.NCS + 1) or HBA selects the command to issue that has had the PxCI bit set to '1' longer than any other command pending to be issued. The result is that commands posted sequentially (time-wise) may play out of sequence when issued by hardware. This behavior has likely been hidden by drives that arrange for commands to complete in issue order. However, it appears recent drives (two from different vendors that we have found so far) inflict out-of-order completions as a matter of course. So, we need to take care to maintain ordered submission, otherwise we risk triggering a drive to fall out of sequential-io automation and back to random-io processing, which incurs large latency and degrades throughput. This issue was found in simple benchmarks where QD=2 seq-write performance was 30-50% *greater* than QD=32 seq-write performance. Tagging for -stable and making the change globally since it has a low risk-to-reward ratio. Also, word is that recent versions of an unnamed OS also does it this way now. So, drives in the field are already experienced with this tag ordering scheme. Cc: Cc: Dave Jiang Cc: Ed Ciechanowski Reviewed-by: Matthew Wilcox Signed-off-by: Dan Williams Signed-off-by: Tejun Heo

libata: remove unused ata_sas_port_async_resume() stub

2014-03-19T20:30:23+00:00

Commit bc6e7c4b0d1a "libata, libsas: kill pm_result and related cleanup" renamed ata_sas_port_async_resume() to ata_sas_port_resume(), but missed a CONFIG_PM=n stub conversion. Randy fixed that up in commit a5a6569959fc "libata.h: add stub for ata_sas_port_resume", but missed the deletion of the now unused ata_sas_port_async_resume() routine. Cc: Randy Dunlap Signed-off-by: Dan Williams Signed-off-by: Tejun Heo

libata.h: add stub for ata_sas_port_resume

2014-03-19T17:56:40+00:00

Fix build error when CONFIG_PM is not enabled by adding a stub function in . drivers/scsi/libsas/sas_ata.c: In function 'sas_resume_sata': drivers/scsi/libsas/sas_ata.c:756:3: error: implicit declaration of function 'ata_sas_port_resume' [-Werror=implicit-function-declaration] Signed-off-by: Randy Dunlap Reported-by: Jim Davis Signed-off-by: Tejun Heo Cc: Dan Williams

libata, libsas: kill pm_result and related cleanup

2014-03-18T20:08:38+00:00

Tejun says: "At least for libata, worrying about suspend/resume failures don't make whole lot of sense. If suspend failed, just proceed with suspend. If the device can't be woken up afterwards, that's that. There isn't anything we could have done differently anyway. The same for resume, if spinup fails, the device is dud and the following commands will invoke EH actions and will eventually fail. Again, there really isn't any *choice* to make. Just making sure the errors are handled gracefully (ie. don't crash) and the following commands are handled correctly should be enough." The only libata user that actually cares about the result from a suspend operation is libsas. However, it only cares about whether queuing a new operation collides with an in-flight one. All libsas does with the error is retry, but we can just let libata wait for the previous operation before continuing. Other cleanups include: 1/ Unifying all ata port pm operations on an ata_port_pm_ prefix 2/ Marking all ata port pm helper routines as returning void, only ata_port_pm_ entry points need to fake a 0 return value. 3/ Killing ata_port_{suspend|resume}_common() in favor of calling ata_port_request_pm() directly 4/ Killing the wrappers that just do a to_ata_port() conversion 5/ Clearly marking the entry points that do async operations with an _async suffix. Reference: http://marc.info/?l=linux-scsi&m=138995409532286&w=2 Cc: Phillip Susi Cc: Alan Stern Suggested-by: Tejun Heo Signed-off-by: Todd Brandt Signed-off-by: Dan Williams Signed-off-by: Tejun Heo

libata: disable LPM for some WD SATA-I devices

2014-01-16T14:49:10+00:00

For some reason, some early WD drives spin up and down drives erratically when the link is put into slumber mode which can reduce the life expectancy of the device significantly. Unfortunately, we don't have full list of devices and given the nature of the issue it'd be better to err on the side of false positives than the other way around. Let's disable LPM on all WD devices which match one of the known problematic model prefixes and are SATA-I. As horkage list doesn't support matching SATA capabilities, this is implemented as two horkages - WD_BROKEN_LPM and NOLPM. The former is set for the known prefixes and sets the latter if the matched device is SATA-I. Note that this isn't optimal as this disables all LPM operations and partial link power state reportedly works fine on these; however, the way LPM is implemented in libata makes it difficult to precisely map libata LPM setting to specific link power state. Well, these devices are already fairly outdated. Let's just disable whole LPM for now. Signed-off-by: Tejun Heo Reported-and-tested-by: Nikos Barkas Reported-and-tested-by: Ioannis Barkas References: https://bugzilla.kernel.org/show_bug.cgi?id=57211 Cc: stable@vger.kernel.org

libata: implement ATA_HORKAGE_NO_NCQ_TRIM and apply it to Micro M500 SSDs

2013-12-17T12:03:14+00:00

Certain drives cannot handle queued TRIM commands properly, even though support is indicated in the IDENTIFY DEVICE buffer. This patch allows for disabling the commands for the affected drives and apply it to the Micron/Crucial M500 SSDs which exhibit incorrect protocol behavior when issued queued TRIM commands, which could lead to silent data corruption. tj: Merged two unnecessarily split patches and made minor edits including shortening horkage name. Signed-off-by: Marc Carino Signed-off-by: Tejun Heo Link: http://lkml.kernel.org/g/1387246554-7311-1-git-send-email-marc.ceeeee@gmail.com Cc: stable@vger.kernel.org # 3.12+

libata: Add support for queued DSM TRIM

2013-08-25T13:39:12+00:00

Some new SSDs support the queued version of the DSM TRIM command. Let the driver use the new command if supported. Signed-off-by: Marc Carino Signed-off-by: Tejun Heo

libata: Add support for SEND/RECEIVE FPDMA QUEUED

2013-08-25T13:39:12+00:00

Add support for the following ATA opcodes, which are present in SATA 3.1 and T13 ATA ACS-3: SEND FPDMA QUEUED RECEIVE FPDMA QUEUED Signed-off-by: Marc Carino Signed-off-by: Tejun Heo

libata: Add H2D FIS "auxiliary" port flag

2013-08-25T13:39:12+00:00

Add a new port flag, ATA_FLAG_FPDMA_AUX, used to indicate support for transmission of the H2D FIS 'auxiliary' field. Signed-off-by: Marc Carino Signed-off-by: Tejun Heo

libata: Populate host-to-device FIS "auxiliary" field

2013-08-25T13:39:11+00:00

SATA 3.1 added an "auxiliary" field to the host-to-device FIS. Populate the host-to-device FIS with the new field via the taskfile struct. Signed-off-by: Marc Carino Signed-off-by: Tejun Heo