Hi Alan, I am not worried about the stack trace . I am worried is the USB is getting disconnected automatically. Then it debounce back to Highspeed . Regards, Shaiju. -----Original Message----- From: Alan Stern [mailto:stern@xxxxxxxxxxxxxxxxxxx] Sent: Saturday, July 28, 2012 9:18 AM To: Sadasivan Shaiju Cc: Peter Chen; shaiju shaiju; USB list Subject: RE: usb hub is n't recognised during boot up(sometimes) On Fri, 27 Jul 2012, Sadasivan Shaiju wrote: > Hi Peter, > > I see the following error in our system . Any idea why this is > happening ? > > ................................................................. > > [ 87.929163] hub 1-0:1.0: state 7 ports 6 chg 0000 evt 0004 > [ 87.929178] ehci_hcd 0000:00:1a.7: GetStatus port 2 status 001002 POWER > sig=se0 CSC > [ 87.929187] hub 1-0:1.0: port 2, status 0100, change 0001, 12 Mb/s > [ 87.929191] usb 1-2: USB disconnect, address 2 > [ 87.929193] usb 1-2: unregistering device > [ 87.929195] usb 1-2: unregistering interface 1-2:1.0 > > .......................................................................... > ..... > ...................................................... > > [ 139.717154] Pid: 265, comm: khubd Tainted: P 2.6.32.39 #3 > [ 139.717157] Call Trace: > [ 139.717165] [<ffffffff81042364>] ? warn_slowpath_common+0x76/0x8c > [ 139.717169] [<ffffffff810efa0b>] ? mark_buffer_dirty+0x23/0x80 > [ 139.717175] [<ffffffff81135ced>] ? ext2_sync_fs+0x7e/0xa4 > [ 139.717178] [<ffffffff810edef0>] ? __sync_filesystem+0x3f/0x50 > [ 139.717182] [<ffffffff810f5168>] ? fsync_bdev+0x1e/0x43 > [ 139.717187] [<ffffffff8119ee6c>] ? bdget_disk+0x2d/0x38 > [ 139.717190] [<ffffffff8119ee93>] ? invalidate_partition+0x1c/0x39 > [ 139.717194] [<ffffffff8111a273>] ? del_gendisk+0x2d/0x10c > [ 139.717198] [<ffffffff811a8b67>] ? kobject_del+0x23/0x2d > [ 139.717203] [<ffffffff81230c27>] ? sd_remove+0x43/0x7c > [ 139.717207] [<ffffffff8121b527>] ? __device_release_driver+0x65/0xb0 > [ 139.717211] [<ffffffff8121b62f>] ? device_release_driver+0x1d/0x28 > [ 139.717214] [<ffffffff8121abc6>] ? bus_remove_device+0xa8/0xbd > [ 139.717218] [<ffffffff81219328>] ? device_del+0x120/0x15e > [ 139.717223] [<ffffffff8122dbb5>] ? __scsi_remove_device+0x4c/0x9b > [ 139.717226] [<ffffffff8122aedd>] ? scsi_forget_host+0x3e/0x5c > [ 139.717230] [<ffffffff81224fa0>] ? scsi_remove_host+0x70/0xf0 > [ 139.717234] [<ffffffff812704be>] ? quiesce_and_remove_host+0x51/0x86 > [ 139.717237] [<ffffffff812705b4>] ? usb_stor_disconnect+0x15/0x1e I think this is a known bug in the buffer management code. It has been fixed in recent kernels, but not in kernels as old as 2.6.32. If you unmount the drive before unplugging it, the bug shouldn't occur. Alan Stern -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
