I can confirm the bug and the workaround (thanks to on rbiscosi) on Linux gue704 2.6.20-16-386 #2 Thu Jun 7 20:16:13 UTC 2007 i686 GNU/Linux
I connected my external Freecom Classic HD twice: 1. Working: With the following line in /etc/modprobe.d/options (working fine): options usb-storage delay_use=8 dmesg: ... [ 559.650682] USB Mass Storage support registered. [ 567.646928] usb-storage: device scan complete [ 567.649923] scsi 2:0:0:0: Direct-Access HDT72252 5DLAT80 V44O PQ: 0 ANSI: 0 [ 567.656845] SCSI device sdc: 488397168 512-byte hdwr sectors (250059 MB) [ 567.661841] sdc: Write Protect is off [ 567.661851] sdc: Mode Sense: 03 00 00 00 [ 567.661856] sdc: assuming drive cache: write through [ 567.666829] SCSI device sdc: 488397168 512-byte hdwr sectors (250059 MB) [ 567.671835] sdc: Write Protect is off [ 567.671844] sdc: Mode Sense: 03 00 00 00 [ 567.671848] sdc: assuming drive cache: write through [ 567.671857] sdc: sdc1 [ 567.693511] sd 2:0:0:0: Attached scsi disk sdc [ 567.693954] sd 2:0:0:0: Attached scsi generic sg2 type 0 [ 653.658001] usb 1-2: USB disconnect, address 3 ... 2. Buggy: After unmounting and disconnecting my HD, I commented out the above mentioned line in /etc/modprobe.d/options and executed (as root): # rmmod usb-storage dmesg: ... [ 1145.427340] USB Mass Storage support registered. [ 1151.421490] usb-storage: device scan complete [ 1153.448783] scsi 3:0:0:0: Direct-Access HDT72252 5DLAT80 V44O PQ: 0 ANSI: 0 [ 1153.454682] SCSI device sdc: 488397168 512-byte hdwr sectors (250059 MB) [ 1153.570520] usb 1-2: reset full speed USB device using uhci_hcd and address 4 [ 1158.733147] usb 1-2: failed to restore interface 0 altsetting 0 (error=-110) [ 1158.733206] usb 1-2: USB disconnect, address 4 [ 1158.733431] BUG: unable to handle kernel NULL pointer dereference at virtual address 00000000 [ 1158.733439] printing eip: [ 1158.733442] c023dd25 [ 1158.733445] *pde = 00000000 [ 1158.733452] Oops: 0000 [#1] ... While the disk worked fine when there are 8 seconds, the 6 seconds are not enough to spin up the device (see the first two lines in the dmegs blocks). Thereafter, rmmod usb-storage and all commands like lsusb run eternally and cannot be interrupted by ctrl-C. Neither is another USB mass storage device working. My hardware is a bit old so it only supports USB 1.1 # lsusb Bus 002 Device 001: ID 0000:0000 Bus 001 Device 003: ID 07ab:fccd Freecom Technologies Bus 001 Device 002: ID 05e3:0605 Genesys Logic, Inc. USB 2.0 Hub [ednet] Bus 001 Device 001: ID 0000:0000 My lspci -vv and -vvn can be found at http://launchpadlibrarian.net/8083791/20lspci-vv and http://launchpadlibrarian.net/8083792/20lspci-vvn ** Attachment added: "dmesg" http://launchpadlibrarian.net/8150814/dmesg -- USB khubd oopsing when attaching usb-storage device https://bugs.launchpad.net/bugs/83748 You received this bug notification because you are a member of Ubuntu Bugs, which is the bug contact for Ubuntu. -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
