Comment 22 for bug 570049

Hi Dave,

what made me file my logs here is that both the symptom (lsusb hanging) and what looks like the underlying cause are both the same. A crash of khubd kernel thread is always there, with a similar stack trace in every case, triggered by the same pattern: usb_stor_disconnect -> usb_stor_disconnect -> kthread_stop -> ...

E.g. this is from a post above:

[ 1680.200076] khubd D 000164da 0 22 2 0x00000000
[ 1680.200086] f710bd34 00000046 e68a0000 000164da 00000000 c0848760 f7100f64 c0848760
[ 1680.200099] 7478828a 0000011c c0848760 c0848760 f7100f64 c0848760 c0848760 f2616000
[ 1680.200110] 00000000 0000011c f7100cc0 7fffffff 7fffffff e68a1fc8 f710bd94 c058c1ed
[ 1680.200121] Call Trace:
[ 1680.200138] [<c058c1ed>] schedule_timeout+0x1ad/0x280
[ 1680.200148] [<c014926b>] ? check_preempt_wakeup+0x20b/0x370
[ 1680.200157] [<c0132c0e>] ? enqueue_task+0x7e/0xa0
[ 1680.200165] [<c058bea6>] wait_for_common+0xa6/0x130
[ 1680.200174] [<c014248f>] ? try_to_wake_up+0x2ef/0x4a0
[ 1680.200182] [<c0142640>] ? default_wake_function+0x0/0x20
[ 1680.200200] [<c058bfe7>] wait_for_completion+0x17/0x20
[ 1680.200208] [<c016790f>] kthread_stop+0x3f/0xa0
[ 1680.200223] [<f809cf68>] release_everything+0x28/0xb0 [usb_storage]
[ 1680.200236] [<f809d00f>] usb_stor_disconnect+0x1f/0x30 [usb_storage]
[ 1680.200244] [<c044bd06>] usb_unbind_interface+0x46/0x130
[ 1680.200254] [<c03e7fa1>] __device_release_driver+0x51/0xb0
[ 1680.200260] [<c03e80c5>] device_release_driver+0x25/0x40
[ 1680.200269] [<c03e737b>] bus_remove_device+0x7b/0xa0
[ 1680.200277] [<c03e57f7>] device_del+0xf7/0x180
[ 1680.200283] [<c0448b13>] usb_disable_device+0x63/0x110
[ 1680.200292] [<c04435fe>] usb_disconnect+0x9e/0x120
[ 1680.200300] [<c0443b5b>] hub_port_connect_change+0x8b/0x890
[ 1680.200307] [<c0449785>] ? usb_control_msg+0xd5/0x130
[ 1680.200315] [<c0441590>] ? clear_port_feature+0x50/0x60
[ 1680.200323] [<c0444b05>] hub_events+0x1f5/0x510
[ 1680.200330] [<c0167cbf>] ? finish_wait+0x4f/0x70
[ 1680.200337] [<c0444e5a>] hub_thread+0x3a/0x140
[ 1680.200344] [<c0167b50>] ? autoremove_wake_function+0x0/0x50
[ 1680.200352] [<c0444e20>] ? hub_thread+0x0/0x140
[ 1680.200358] [<c01678c4>] kthread+0x74/0x80
[ 1680.200365] [<c0167850>] ? kthread+0x0/0x80
[ 1680.200373] [<c0104087>] kernel_thread_helper+0x7/0x10

while this is mine:

[42722.411019] Call Trace:
[42722.411030] [<ffffffff815c85dd>] schedule_timeout+0x26d/0x2e0
[42722.411038] [<ffffffff810576a3>] ? update_curr+0x103/0x210
[42722.411044] [<ffffffff815c8099>] wait_for_common+0xd9/0x180
[42722.411049] [<ffffffff8105f690>] ? default_wake_function+0x0/0x20
[42722.411056] [<ffffffff815c821d>] wait_for_completion+0x1d/0x20
[42722.411061] [<ffffffff810879e2>] kthread_stop+0x42/0xf0
[42722.411068] [<ffffffffa02375fe>] release_everything+0x2e/0xb0 [usb_storage]
[42722.411074] [<ffffffffa02384ca>] usb_stor_disconnect+0x2a/0x40 [usb_storage]
[42722.411081] [<ffffffff8144464a>] usb_unbind_interface+0x5a/0x1a0
[42722.411089] [<ffffffff813bb305>] __device_release_driver+0x75/0xe0
[42722.411093] [<ffffffff813bb39d>] device_release_driver+0x2d/0x40
[42722.411097] [<ffffffff813bae4b>] bus_remove_device+0x7b/0xa0
[42722.411102] [<ffffffff813b80e7>] device_del+0x127/0x1b0
[42722.411106] [<ffffffff81442404>] usb_disable_device+0x74/0x130
[42722.411112] [<ffffffff8143b4e5>] usb_disconnect+0x95/0x130
[42722.411116] [<ffffffff81440aa8>] ? usb_init_urb+0x28/0x40
[42722.411120] [<ffffffff8143c29d>] hub_port_connect_change+0x9d/0x930
[42722.411125] [<ffffffff8143ce72>] hub_events+0x342/0x4e0
[42722.411130] [<ffffffff8143d045>] hub_thread+0x35/0x180
[42722.411134] [<ffffffff810880e0>] ? autoremove_wake_function+0x0/0x40
[42722.411138] [<ffffffff8143d010>] ? hub_thread+0x0/0x180
[42722.411141] [<ffffffff81087996>] kthread+0x96/0xa0
[42722.411147] [<ffffffff8100ce24>] kernel_thread_helper+0x4/0x10
[42722.411152] [<ffffffff81087900>] ? kthread+0x0/0xa0
[42722.411155] [<ffffffff8100ce20>] ? kernel_thread_helper+0x0/0x10