http://bugzilla.kernel.org/show_bug.cgi?id=12730 Summary: USB memory stick moved to different device on error / may be due to problem with high concurrent load on two USB devices Product: IO/Storage Version: 2.5 KernelVersion: 2.6.27.17 Platform: All OS/Version: Linux Tree: Mainline Status: NEW Severity: normal Priority: P1 Component: SCSI AssignedTo: linux-scsi@xxxxxxxxxxxxxxx ReportedBy: wagner@xxxxxxxxxxxxxx Latest working kernel version: No idea Earliest failing kernel version: No idea Distribution: Debian Lenny Hardware Environment: USB is EHCI by ATI/AMD SB600. CPU is a single core Sempron LE-1250 Software Environment: dd_rescue and a self-written flash exerciser Problem Description: I have a 2GB flash as /dev/sdd and a 16GB flash as /dev/sde. The 2 GB is exercised by a tester that writes and verifies. (This is intended to be run until there are read errors. I expect that may take up to a year or longer.) The 16GB I wanted to do a speed test using dd_rescue /dev/sde /dev/null. It seems this somehow caused a problem leadung to high volume console output and USB disconnects for both devices (found in the logs). I have tried the read from the 16GB without the exerciser running, this seems to work. Unfortunately I did not find any error diagnotics in the logs besides the USB disconnect, at least not anythign I recognized. What I did should not have caused USB disconnects in the first place, so this may also be an USB driver problem or the like. Now the interesting thing is that the kernel seems to have disabled /dev/sdd and used the 16GB flash as new /dev/sdd. The 2GB flash did not turn up again. Not good, devices should not change without an explicit re-plug. If an USB disconnect is indistinguishable in software from a physical unplug and replug, I understand that nothing can be done. But if it can be distinguished, devices should be prevented from moving around on error. Steps to reproduce: I tried to run this again. Just a reading of the 16GB flash with dd_rescue did not produce any problems. Starting the flash exerciser again after replugging both flash devices to get them to their original devices worked. I could not recreate the original situation, since the port with the 2GB device was now only using OHCI and a reboot on this machine causes some effort. This may therefore also be an USB driver issue with the EHCI driver being crashy. -- Configure bugmail: http://bugzilla.kernel.org/userprefs.cgi?tab=email ------- You are receiving this mail because: ------- You are the assignee for the bug, or are watching the assignee. -- 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
