Patrick: Cornelius Claussen reported the following problem with error recovery in 2.6.0-test11. His device is one of those problem-prone Genesys Logic units, a USB DVD drive. The complete message and log can be found at
http://marc.theaimsgroup.com/?l=linux-usb-devel&m=107134787817252&w=2 Here's a condensed and annotated version of his log: usb-storage: Command READ_10 (10 bytes) usb-storage: 28 00 00 00 b6 91 00 00 2e 00 usb-storage: Status code -75; transferred 68096/94208 usb-storage: -- babble usb-storage: -- transport indicates error, resetting usb-storage: Soft reset done usb-storage: scsi cmd done, result=0x70000 The device messed up; to recover we had to send it a soft reset command. The scmd->result code was DID_ERROR << 16. The SCSI layer retried the command: usb-storage: Command READ_10 (10 bytes) usb-storage: 28 00 00 00 b6 91 00 00 2e 00 usb-storage: -- transport indicates command failure usb-storage: -- unexpectedly short transfer usb-storage: Issuing auto-REQUEST_SENSE usb-storage: -- code: 0x70, key: 0x6, ASC: 0x29, ASCQ: 0x0 usb-storage: Unit Attention: Power on, reset, or bus device reset occurred usb-storage: scsi cmd done, result=0x2 The device reported the reset via Unit Attention. The scmd->result code was SAM_STAT_CHECK_CONDITION. Presumably another retry at this point would have worked. Instead he got... end_request: I/O error, dev sr1, sector 186948 Buffer I/O error on device sr1, logical block 46737 Buffer I/O error on device sr1, logical block 46738 etc. In fact, another READ command queued shortly afterward, usb-storage: Command READ_10 (10 bytes) usb-storage: 28 00 00 00 b6 bf 00 00 3c 00 usb-storage: Bulk Status S 0x53425355 T 0xec9 R 2048 Stat 0x0 usb-storage: scsi cmd done, result=0x0 succeeded, albeit with a residue of 2048. But by then it was too late, the original request had failed. What's the right way to fix this? Alan Stern ------------------------------------------------------- This SF.net email is sponsored by: IBM Linux Tutorials. Become an expert in LINUX or just sharpen your skills. Sign up for IBM's Free Linux Tutorials. Learn everything from the bash shell to sys admin. Click now! http://ads.osdn.com/?ad_id=1278&alloc_id=3371&op=click _______________________________________________ [EMAIL PROTECTED] To unsubscribe, use the last form field at: https://lists.sourceforge.net/lists/listinfo/linux-usb-devel
