Hello, I've just plugged+unplugged+plugged my USB audio card and the audio subsystem got stuck: INFO: task khubd:440 blocked for more than 120 seconds. "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. khubd D ffff8801cbc92400 0 440 2 0x00000000 ffff8801c4ae3a38 0000000000000046 ffff8801c49be270 ffff8801c4ae3fd8 ffff8801c4ae3fd8 ffff8801c4ae3fd8 ffff8801c4284830 ffff8801c49be270 ffff8801c4ae3a28 ffff8801a7198758 ffff8801a719875c ffff8801c49be270 Call Trace: [<ffffffff816ae109>] schedule+0x29/0x70 [<ffffffff816ae38e>] schedule_preempt_disabled+0xe/0x10 [<ffffffff816ad02a>] __mutex_lock_slowpath+0xca/0x140 [<ffffffff816acb5a>] mutex_lock+0x2a/0x50 [<ffffffff8157c8e6>] snd_pcm_dev_disconnect+0x46/0x1f0 [<ffffffff81576512>] snd_device_disconnect+0x62/0xa0 [<ffffffff815765f4>] snd_device_disconnect_all+0x44/0x70 [<ffffffff81570d83>] snd_card_disconnect+0x153/0x1d0 [<ffffffff816ad3a8>] ? down_write+0x38/0x40 [<ffffffff815bf038>] usb_audio_disconnect+0x88/0x1c0 [<ffffffff814df460>] usb_unbind_interface+0x60/0x1a0 [<ffffffff81436e4c>] __device_release_driver+0x7c/0xe0 [<ffffffff814370bc>] device_release_driver+0x2c/0x40 [<ffffffff8143681e>] bus_remove_device+0xee/0x160 [<ffffffff81433c2a>] device_del+0x11a/0x1b0 [<ffffffff814dce40>] usb_disable_device+0xb0/0x270 [<ffffffff814d38ed>] usb_disconnect+0xad/0x160 [<ffffffff814d613e>] hub_thread+0x6fe/0x1700 [<ffffffff810b643e>] ? dequeue_task_fair+0xee/0x100 [<ffffffff810a2c70>] ? finish_wait+0x80/0x80 [<ffffffff814d5a40>] ? usb_remote_wakeup+0x70/0x70 [<ffffffff810a2620>] kthread+0xc0/0xd0 [<ffffffff810a2560>] ? kthread_create_on_node+0x130/0x130 [<ffffffff816afb5c>] ret_from_fork+0x7c/0xb0 [<ffffffff810a2560>] ? kthread_create_on_node+0x130/0x130 INFO: task pulseaudio:4642 blocked for more than 120 seconds. "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. pulseaudio D ffff8801cbc12400 0 4642 1 0x00000000 ffff8801c1c39cf0 0000000000000082 ffff8801c0d7d550 ffff8801c1c39fd8 ffff8801c1c39fd8 ffff8801c1c39fd8 ffff8801a7203480 ffff8801c0d7d550 ffff8801aa37b530 ffff8801c0d7d550 ffff8800ab118a48 fffffffeffffffff Call Trace: [<ffffffff816ae109>] schedule+0x29/0x70 [<ffffffff816aeafd>] rwsem_down_failed_common+0xbd/0x150 [<ffffffff816aebc5>] rwsem_down_read_failed+0x15/0x17 [<ffffffff81302c04>] call_rwsem_down_read_failed+0x14/0x30 [<ffffffff816ad3d4>] ? down_read+0x24/0x2b [<ffffffff815c84b2>] snd_usb_hw_free+0x42/0x90 [<ffffffff815809ab>] snd_pcm_release_substream+0x5b/0xc0 [<ffffffff81580a58>] snd_pcm_release+0x48/0xb0 [<ffffffff815707d7>] snd_disconnect_release+0x97/0xe0 [<ffffffff8116ed8c>] __fput+0xec/0x230 [<ffffffff8116eede>] ____fput+0xe/0x10 [<ffffffff8109ef37>] task_work_run+0xa7/0xe0 [<ffffffff81045959>] do_notify_resume+0x59/0x80 [<ffffffff816afe08>] int_signal+0x12/0x17 INFO: task khubd:440 blocked for more than 120 seconds. "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. khubd D ffff8801cbc92400 0 440 2 0x00000000 ffff8801c4ae3a38 0000000000000046 ffff8801c49be270 ffff8801c4ae3fd8 ffff8801c4ae3fd8 ffff8801c4ae3fd8 ffff8801c4284830 ffff8801c49be270 ffff8801c4ae3a28 ffff8801a7198758 ffff8801a719875c ffff8801c49be270 Call Trace: [<ffffffff816ae109>] schedule+0x29/0x70 [<ffffffff816ae38e>] schedule_preempt_disabled+0xe/0x10 [<ffffffff816ad02a>] __mutex_lock_slowpath+0xca/0x140 [<ffffffff816acb5a>] mutex_lock+0x2a/0x50 [<ffffffff8157c8e6>] snd_pcm_dev_disconnect+0x46/0x1f0 [<ffffffff81576512>] snd_device_disconnect+0x62/0xa0 [<ffffffff815765f4>] snd_device_disconnect_all+0x44/0x70 [<ffffffff81570d83>] snd_card_disconnect+0x153/0x1d0 [<ffffffff816ad3a8>] ? down_write+0x38/0x40 [<ffffffff815bf038>] usb_audio_disconnect+0x88/0x1c0 [<ffffffff814df460>] usb_unbind_interface+0x60/0x1a0 [<ffffffff81436e4c>] __device_release_driver+0x7c/0xe0 [<ffffffff814370bc>] device_release_driver+0x2c/0x40 [<ffffffff8143681e>] bus_remove_device+0xee/0x160 [<ffffffff81433c2a>] device_del+0x11a/0x1b0 [<ffffffff814dce40>] usb_disable_device+0xb0/0x270 [<ffffffff814d38ed>] usb_disconnect+0xad/0x160 [<ffffffff814d613e>] hub_thread+0x6fe/0x1700 [<ffffffff810b643e>] ? dequeue_task_fair+0xee/0x100 [<ffffffff810a2c70>] ? finish_wait+0x80/0x80 [<ffffffff814d5a40>] ? usb_remote_wakeup+0x70/0x70 [<ffffffff810a2620>] kthread+0xc0/0xd0 [<ffffffff810a2560>] ? kthread_create_on_node+0x130/0x130 [<ffffffff816afb5c>] ret_from_fork+0x7c/0xb0 [<ffffffff810a2560>] ? kthread_create_on_node+0x130/0x130 sadc D ffff8801cbc92400 0 7883 7870 0x00000004 ffff8801b9ab5d98 0000000000000082 ffff8801087b0d20 ffff8801b9ab5fd8 ffff8801b9ab5fd8 ffff8801b9ab5fd8 ffff8801c487c830 ffff8801087b0d20 ffff8801c0ca5380 ffff8801b99b08e8 ffff8801b99b08ec ffff8801087b0d20 Call Trace: [<ffffffff816ae109>] schedule+0x29/0x70 [<ffffffff816ae38e>] schedule_preempt_disabled+0xe/0x10 [<ffffffff816ad02a>] __mutex_lock_slowpath+0xca/0x140 [<ffffffff816acb5a>] mutex_lock+0x2a/0x50 [<ffffffff814e312b>] show_manufacturer+0x2b/0x60 [<ffffffff81433910>] dev_attr_show+0x20/0x60 [<ffffffff81129707>] ? __get_free_pages+0x17/0x50 [<ffffffff811d6fc5>] sysfs_read_file+0xa5/0x1c0 [<ffffffff8116dcb9>] vfs_read+0xa9/0x180 [<ffffffff8116dde2>] sys_read+0x52/0xa0 [<ffffffff816afc02>] system_call_fastpath+0x16/0x1b thanks, -- js suse labs -- 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