Updated bug description below. On Fri, Apr 16, 2010 at 03:25:42PM -0400, Alan Stern wrote: > On Fri, 16 Apr 2010, Sarah Sharp wrote: > > > In the meantime, can everyone confirm my summary of the behavior of the > > Buffalo device (not the Genesys chip)? > > > > > > > > > > There seems to be an issue with how the Buffalo USB3 hard drive handles > > the SCSI ATA pass through commands. We found this issue when the Linux > > userspace program hdparm, using the Ubuntu Linux distribution. The > > device responds correctly to an IDENTIFY DEVICE via the ATA_12 tunnel, > > but it stalls when it's sent an IDENTIFY DEVICE via the ATA_16 tunnel. > > "Stalls" isn't the right word. It responds with "Phase Error" in > bCSWStatus. Less precisely but more succinctly, it returns a Phase > Error. > > > The command before the ATA_16 IDENTIFY DEVICE was a SET FEATURES via the > > ATA_16 tunnel, and it was responded to properly, so we think it should > > support the ATA_16 commands. > > > > This problem makes the device unusable under the Linux 2.6.31 and 2.6.32 > > Only when running USB 3. The devices work okay with USB 2. > > > kernels, as they don't support configured device reset after an endpoint > > stall. The device works on later kernels (2.6.33 and 2.6.34) with that > > support. > > > > > > Details > > ------- > > > > The hdparm program issues the following commands, and gets the following > > responses: > > > > command contents: a1 08 2e 00 01 00 00 00 00 ec 00 00 > > Bulk Command S 0x43425355 T 0x2d L 512 F 128 Trg 0 LUN 0 CL 12 > > Bulk Status S 0x53425355 T 0x2d R 0 Stat 0x0 > > scsi cmd done, result=0x0 > > (This is an IDENTIFY DEVICE via the ATA_12 tunnel) > > > > command contents: 85 06 20 00 05 00 fe 00 00 00 00 00 00 40 ef 00 > > Bulk Command S 0x43425355 T 0x2e L 0 F 0 Trg 0 LUN 0 CL 16 > > Bulk Command S 0x43425355 T 0x2f L 512 F 128 Trg 0 LUN 0 CL 16 > > This "T 0x2f" line doesn't belong here (it appears below). Copy & > Paste error? > > > Bulk Status S 0x53425355 T 0x2e R 0 Stat 0x0 > > scsi cmd done, result=0x0 > > (This is a SET FEATURES via the ATA_16 tunnel) > > > > command contents: 85 08 2e 00 00 00 00 00 00 00 00 00 00 40 ec 00 > > Bulk Command S 0x43425355 T 0x2f L 512 F 128 Trg 0 LUN 0 CL 16 > > Bulk Status S 0x53425355 T 0x2f R 512 Stat 0x2 > > And this "Bulk Status" line doesn't belong here. Again, it appears > below. > > > Status code -32; transferred 0/512 > > clearing endpoint halt for pipe 0xc0008280 > > Bulk status result = 0 > > Bulk Status S 0x53425355 T 0x2f R 512 Stat 0x2 > > -- transport indicates error, resetting > > (This is an IDENTIFY DEVICE via the ATA_16 tunnel) > > > > The full log is here: > > http://minilop.net/~sarah/buffalo-hd-ata-16-issue.log > > > > The drive stalls on the last command, which is a valid ATA command. Can > > It returns an error on the last command. (It also stalls, but that's > okay -- stalling an endpoint during a command is normal and it should > work fine with USB 3.) > > > you confirm if your device supports the SCSI ATA pass through > > specification? > > > > http://www.t10.org/cgi-bin/ac.pl?t=f&f=sat2r09.pdf > > That link doesn't work. The standard is not freely available. > > Alan Stern > Updated description ------------------- Summary: The Buffalo USB3 hard drive fails to mount after being sent an ATA_16 IDENTIFY command. It does not fail when the device is connected via a USB 2.0 cable and the same command is sent. Details: There seems to be an issue with how the Buffalo USB3 hard drive handles the SCSI ATA pass through commands. We found this issue with the Linux userspace program hdparm, using the Ubuntu Linux Karmic distribution. The device responds correctly to an IDENTIFY DEVICE via the ATA_12 tunnel, but it responds with a Phase Error when it's sent an IDENTIFY DEVICE via the ATA_16 tunnel, and then stalls. The hdparm program thinks the Phase Error is an invalid response: sudo hdparm --verbose /dev/sdb /dev/sdb: outgoing cdb: 85 08 2e 00 00 00 00 00 00 00 00 00 00 40 ec 00 SG_IO: ATA_16 status=0x0, host_status=0x7, driver_status=0x0 SG_IO: bad response (not CHECK_CONDITION) outgoing cdb: 85 08 2e 00 00 00 00 00 00 00 00 00 00 40 a1 00 SG_IO: ATA_16 status=0x0, host_status=0x7, driver_status=0x0 SG_IO: bad response (not CHECK_CONDITION) HDIO_DRIVE_CMD(identify) failed: Invalid exchange readonly = 0 (off) readahead = 256 (on) geometry = 36365/64/32, sectors = 0, start = 0 Stalling on the ATA_16 IDENTIFY device is fine, but the invalid response is not. The hard drive does not seem to work after this command is sent, and cannot be mounted. If we inhibit udev from running hdparm (by stopping the udev daemon) then the drive can be mounted successfully. If the drive is plugged in via a USB 2.0 cable, then the drive works correctly, even though it gets issued the same commands. The command before the ATA_16 IDENTIFY DEVICE was a SET FEATURES via the ATA_16 tunnel, and it was responded to properly, so we think it should support the ATA_16 commands. The full kernel log is here: http://minilop.net/~sarah/buffalo-hd-ata-16-issue.log The ATA_12 IDENTIFY command starts at line 8816. (It says the command is a BLANK command, but it's incorrectly identified that command.) Sarah Sharp -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
