From: Jiri Slaby <jslaby@suse.cz>
To: Takashi Iwai <tiwai@suse.de>
Cc: Jaroslav Kysela <perex@perex.cz>,
alsa-devel@alsa-project.org, LKML <linux-kernel@vger.kernel.org>,
USB list <linux-usb@vger.kernel.org>,
Jiri Slaby <jirislaby@gmail.com>
Subject: Re: Sound+USB: deadlock problem
Date: Tue, 13 Nov 2012 10:39:14 +0100 [thread overview]
Message-ID: <50A21542.2090102@suse.cz> (raw)
In-Reply-To: <s5h7gppx568.wl%tiwai@suse.de>
On 11/13/2012 09:45 AM, Takashi Iwai wrote:
> At Tue, 13 Nov 2012 09:30:10 +0100,
> Jiri Slaby wrote:
>>
>> On 11/13/2012 09:28 AM, Takashi Iwai wrote:
>>> At Tue, 13 Nov 2012 09:26:17 +0100,
>>> Jiri Slaby wrote:
>>>>
>>>> Hello,
>>>>
>>>> I've just plugged+unplugged+plugged my USB audio card and the audio
>>>> subsystem got stuck:
>>>
>>> Which kernel? If it's older than 3.7-rc5, could you try 3.7-rc5?
>>
>> Oh, forgot to mention:
>> 3.7.0-rc5-next-20121112_64+
>
> Through a quick glance, one of mutex locks seems stuck.
> Just a blind short -- does the patch below cure the problem?
Yes, this helps.
Adding a LOCKDEP splash _before_ applying the patch:
======================================================
[ INFO: possible circular locking dependency detected ]
3.7.0-rc5-next-20121112_64-ldep+ #15 Not tainted
-------------------------------------------------------
khubd/446 is trying to acquire lock:
(&pcm->open_mutex){+.+.+.}, at: [<ffffffff8154c555>]
snd_pcm_dev_disconnect+0x45/0x1f0
but task is already holding lock:
(register_mutex#2){+.+.+.}, at: [<ffffffff8154c533>]
snd_pcm_dev_disconnect+0x23/0x1f0
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #2 (register_mutex#2){+.+.+.}:
[<ffffffff810c5e8a>] lock_acquire+0x5a/0x70
[<ffffffff81697fa9>] mutex_lock_nested+0x69/0x3a0
[<ffffffff8154c533>] snd_pcm_dev_disconnect+0x23/0x1f0
[<ffffffff815462e2>] snd_device_disconnect+0x62/0xa0
[<ffffffff815463bc>] snd_device_disconnect_all+0x3c/0x60
[<ffffffff81540ec7>] snd_card_disconnect+0x147/0x1d0
[<ffffffff8158c328>] usb_audio_disconnect+0x98/0x1d0
[<ffffffff814aa4fe>] usb_unbind_interface+0x5e/0x1a0
[<ffffffff81404ad7>] __device_release_driver+0x77/0xe0
[<ffffffff81404d49>] device_release_driver+0x29/0x40
[<ffffffff814044aa>] bus_remove_device+0xfa/0x170
[<ffffffff81401917>] device_del+0x127/0x1c0
[<ffffffff814a7f20>] usb_disable_device+0xb0/0x270
[<ffffffff8149ea0d>] usb_disconnect+0xad/0x160
[<ffffffff814a12bc>] hub_thread+0x71c/0x1730
[<ffffffff810967e6>] kthread+0xd6/0xe0
[<ffffffff8169c2ec>] ret_from_fork+0x7c/0xb0
-> #1 (&chip->shutdown_rwsem){++++++}:
[<ffffffff810c5e8a>] lock_acquire+0x5a/0x70
[<ffffffff816993b7>] down_read+0x47/0x5c
[<ffffffff8158cf9c>] snd_usb_autoresume+0x2c/0x60
[<ffffffff81594e2f>] snd_usb_pcm_open+0x20f/0x4a0
[<ffffffff815950db>] snd_usb_playback_open+0xb/0x10
[<ffffffff81553c0e>] snd_pcm_open_substream+0x4e/0x90
[<ffffffff81553d02>] snd_pcm_open+0xb2/0x250
[<ffffffff81553f53>] snd_pcm_playback_open+0x43/0x70
[<ffffffff8153fb9a>] snd_open+0xba/0x200
[<ffffffff81152766>] chrdev_open+0x96/0x1c0
[<ffffffff8114c766>] do_dentry_open.isra.16+0x1e6/0x280
[<ffffffff8114c836>] finish_open+0x36/0x70
[<ffffffff8115c53e>] do_last.isra.64+0x2ce/0xcc0
[<ffffffff8115cfe3>] path_openat.isra.65+0xb3/0x4d0
[<ffffffff8115d66c>] do_filp_open+0x3c/0x90
[<ffffffff8114d8af>] do_sys_open+0xef/0x1d0
[<ffffffff8114d9ac>] sys_open+0x1c/0x20
[<ffffffff8169c392>] system_call_fastpath+0x16/0x1b
-> #0 (&pcm->open_mutex){+.+.+.}:
[<ffffffff810c5968>] __lock_acquire+0x1c38/0x1c40
[<ffffffff810c5e8a>] lock_acquire+0x5a/0x70
[<ffffffff81697fa9>] mutex_lock_nested+0x69/0x3a0
[<ffffffff8154c555>] snd_pcm_dev_disconnect+0x45/0x1f0
[<ffffffff815462e2>] snd_device_disconnect+0x62/0xa0
[<ffffffff815463bc>] snd_device_disconnect_all+0x3c/0x60
[<ffffffff81540ec7>] snd_card_disconnect+0x147/0x1d0
[<ffffffff8158c328>] usb_audio_disconnect+0x98/0x1d0
[<ffffffff814aa4fe>] usb_unbind_interface+0x5e/0x1a0
[<ffffffff81404ad7>] __device_release_driver+0x77/0xe0
[<ffffffff81404d49>] device_release_driver+0x29/0x40
[<ffffffff814044aa>] bus_remove_device+0xfa/0x170
[<ffffffff81401917>] device_del+0x127/0x1c0
[<ffffffff814a7f20>] usb_disable_device+0xb0/0x270
[<ffffffff8149ea0d>] usb_disconnect+0xad/0x160
[<ffffffff814a12bc>] hub_thread+0x71c/0x1730
[<ffffffff810967e6>] kthread+0xd6/0xe0
[<ffffffff8169c2ec>] ret_from_fork+0x7c/0xb0
other info that might help us debug this:
Chain exists of:
&pcm->open_mutex --> &chip->shutdown_rwsem --> register_mutex#2
Possible unsafe locking scenario:
CPU0 CPU1
---- ----
lock(register_mutex#2);
lock(&chip->shutdown_rwsem);
lock(register_mutex#2);
lock(&pcm->open_mutex);
*** DEADLOCK ***
6 locks held by khubd/446:
#0: (&__lockdep_no_validate__){......}, at: [<ffffffff814a0c7e>]
hub_thread+0xde/0x1730
#1: (&__lockdep_no_validate__){......}, at: [<ffffffff8149e9c1>]
usb_disconnect+0x61/0x160
#2: (&__lockdep_no_validate__){......}, at: [<ffffffff81404d41>]
device_release_driver+0x21/0x40
#3: (register_mutex#5){+.+.+.}, at: [<ffffffff8158c2c5>]
usb_audio_disconnect+0x35/0x1d0
#4: (&chip->shutdown_rwsem){++++++}, at: [<ffffffff8158c2d5>]
usb_audio_disconnect+0x45/0x1d0
#5: (register_mutex#2){+.+.+.}, at: [<ffffffff8154c533>]
snd_pcm_dev_disconnect+0x23/0x1f0
stack backtrace:
Pid: 446, comm: khubd Not tainted 3.7.0-rc5-next-20121112_64-ldep+ #15
Call Trace:
[<ffffffff81691220>] print_circular_bug+0x1fb/0x20c
[<ffffffff810c5968>] __lock_acquire+0x1c38/0x1c40
[<ffffffff81546a6e>] ? snd_unregister_oss_device+0x9e/0x120
[<ffffffff810c5e8a>] lock_acquire+0x5a/0x70
[<ffffffff8154c555>] ? snd_pcm_dev_disconnect+0x45/0x1f0
[<ffffffff81697fa9>] mutex_lock_nested+0x69/0x3a0
[<ffffffff8154c555>] ? snd_pcm_dev_disconnect+0x45/0x1f0
[<ffffffff8154c555>] snd_pcm_dev_disconnect+0x45/0x1f0
[<ffffffff815462e2>] snd_device_disconnect+0x62/0xa0
[<ffffffff815463bc>] snd_device_disconnect_all+0x3c/0x60
[<ffffffff81540ec7>] snd_card_disconnect+0x147/0x1d0
[<ffffffff8158c328>] usb_audio_disconnect+0x98/0x1d0
[<ffffffff814aa4fe>] usb_unbind_interface+0x5e/0x1a0
[<ffffffff81404ad7>] __device_release_driver+0x77/0xe0
[<ffffffff81404d49>] device_release_driver+0x29/0x40
[<ffffffff814044aa>] bus_remove_device+0xfa/0x170
[<ffffffff81401917>] device_del+0x127/0x1c0
[<ffffffff8149e9c1>] ? usb_disconnect+0x61/0x160
[<ffffffff814a7f20>] usb_disable_device+0xb0/0x270
[<ffffffff8149ea0d>] usb_disconnect+0xad/0x160
[<ffffffff814a12bc>] hub_thread+0x71c/0x1730
[<ffffffff810c689d>] ? trace_hardirqs_on_caller+0x10d/0x1e0
[<ffffffff81096d70>] ? __init_waitqueue_head+0x60/0x60
[<ffffffff814a0ba0>] ? usb_remote_wakeup+0x70/0x70
[<ffffffff810967e6>] kthread+0xd6/0xe0
[<ffffffff8169b65b>] ? _raw_spin_unlock_irq+0x2b/0x50
[<ffffffff81096710>] ? kthread_create_on_node+0x140/0x140
[<ffffffff8169c2ec>] ret_from_fork+0x7c/0xb0
[<ffffffff81096710>] ? kthread_create_on_node+0x140/0x140
--
js
suse labs
next prev parent reply other threads:[~2012-11-13 9:39 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-11-13 8:26 Sound+USB: deadlock problem Jiri Slaby
2012-11-13 8:28 ` Takashi Iwai
2012-11-13 8:30 ` Jiri Slaby
2012-11-13 8:45 ` Takashi Iwai
2012-11-13 9:39 ` Jiri Slaby [this message]
[not found] ` <50A21542.2090102-AlSwsSmVLrQ@public.gmane.org>
2012-11-13 10:16 ` Takashi Iwai
2012-11-13 10:16 ` Takashi Iwai
2012-11-14 10:44 ` Re : " Matthieu CASTET
2012-11-14 14:59 ` Takashi Iwai
2012-11-15 20:01 ` Ben Hutchings
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=50A21542.2090102@suse.cz \
--to=jslaby@suse.cz \
--cc=alsa-devel@alsa-project.org \
--cc=jirislaby@gmail.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-usb@vger.kernel.org \
--cc=perex@perex.cz \
--cc=tiwai@suse.de \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.