linux/sound/usb
Takashi Iwai 0725dda207 ALSA: usb-audio: Fix device_del() sysfs warnings at disconnect
Some USB-audio devices show weird sysfs warnings at disconnecting the
devices, e.g.
 usb 1-3: USB disconnect, device number 3
 ------------[ cut here ]------------
 WARNING: CPU: 0 PID: 973 at fs/sysfs/group.c:216 device_del+0x39/0x180()
 sysfs group ffffffff8183df40 not found for kobject 'midiC1D0'
 Call Trace:
  [<ffffffff814a3e38>] ? dump_stack+0x49/0x71
  [<ffffffff8103cb72>] ? warn_slowpath_common+0x82/0xb0
  [<ffffffff8103cc55>] ? warn_slowpath_fmt+0x45/0x50
  [<ffffffff813521e9>] ? device_del+0x39/0x180
  [<ffffffff81352339>] ? device_unregister+0x9/0x20
  [<ffffffff81352384>] ? device_destroy+0x34/0x40
  [<ffffffffa00ba29f>] ? snd_unregister_device+0x7f/0xd0 [snd]
  [<ffffffffa025124e>] ? snd_rawmidi_dev_disconnect+0xce/0x100 [snd_rawmidi]
  [<ffffffffa00c0192>] ? snd_device_disconnect+0x62/0x90 [snd]
  [<ffffffffa00c025c>] ? snd_device_disconnect_all+0x3c/0x60 [snd]
  [<ffffffffa00bb574>] ? snd_card_disconnect+0x124/0x1a0 [snd]
  [<ffffffffa02e54e8>] ? usb_audio_disconnect+0x88/0x1c0 [snd_usb_audio]
  [<ffffffffa015260e>] ? usb_unbind_interface+0x5e/0x1b0 [usbcore]
  [<ffffffff813553e9>] ? __device_release_driver+0x79/0xf0
  [<ffffffff81355485>] ? device_release_driver+0x25/0x40
  [<ffffffff81354e11>] ? bus_remove_device+0xf1/0x130
  [<ffffffff813522b9>] ? device_del+0x109/0x180
  [<ffffffffa01501d5>] ? usb_disable_device+0x95/0x1f0 [usbcore]
  [<ffffffffa014634f>] ? usb_disconnect+0x8f/0x190 [usbcore]
  [<ffffffffa0149179>] ? hub_thread+0x539/0x13a0 [usbcore]
  [<ffffffff810669f5>] ? sched_clock_local+0x15/0x80
  [<ffffffff81066c98>] ? sched_clock_cpu+0xb8/0xd0
  [<ffffffff81070730>] ? bit_waitqueue+0xb0/0xb0
  [<ffffffffa0148c40>] ? usb_port_resume+0x430/0x430 [usbcore]
  [<ffffffffa0148c40>] ? usb_port_resume+0x430/0x430 [usbcore]
  [<ffffffff8105973e>] ? kthread+0xce/0xf0
  [<ffffffff81059670>] ? kthread_create_on_node+0x1c0/0x1c0
  [<ffffffff814a8b7c>] ? ret_from_fork+0x7c/0xb0
  [<ffffffff81059670>] ? kthread_create_on_node+0x1c0/0x1c0
 ---[ end trace 40b1928d1136b91e ]---

This comes from the fact that usb-audio driver may receive the
disconnect callback multiple times, per each usb interface.  When a
device has both audio and midi interfaces, it gets called twice, and
currently the driver tries to release resources at the last call.
At this point, the first parent interface has been already deleted,
thus deleting a child of the first parent hits such a warning.

For fixing this problem, we need to call snd_card_disconnect() and
cancel pending operations at the very first disconnect while the
release of the whole objects waits until the last disconnect call.

Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=80931
Reported-and-tested-by: Tomas Gayoso <tgayoso@gmail.com>
Reported-and-tested-by: Chris J Arges <chris.j.arges@canonical.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
2014-11-05 15:36:25 +01:00
..
6fire ALSA: 6fire: Use standard printk helpers 2014-02-26 17:22:09 +01:00
bcd2000 ALSA: MIDI driver for Behringer BCD2000 USB device 2014-04-07 16:05:41 +02:00
caiaq ALSA: usb: caiaq: check for cdev->n_streams > 1 2014-10-07 14:34:25 +02:00
hiface ALSA: usb: Convert to snd_card_new() with a device pointer 2014-02-12 11:18:00 +01:00
misc ALSA: usb: Convert to snd_card_new() with a device pointer 2014-02-12 11:18:00 +01:00
usx2y ALSA: usx2y: Don't peep the card internal object 2014-02-17 10:16:25 +01:00
card.c ALSA: usb-audio: Fix device_del() sysfs warnings at disconnect 2014-11-05 15:36:25 +01:00
card.h ALSA: usb-audio: work around corrupted TEAC UD-H01 feedback data 2014-05-02 18:21:55 +02:00
clock.c ALSA: usb-audio: Use standard printk helpers 2014-02-26 16:45:34 +01:00
clock.h ALSA: usb-audio: UAC2: do clock validity check earlier 2013-04-04 08:30:59 +02:00
debug.h
endpoint.c ALSA: usb-audio: Fix races at disconnection and PCM closing 2014-06-26 10:33:35 +02:00
endpoint.h ALSA: usb-audio: Fix races at disconnection and PCM closing 2014-06-26 10:33:35 +02:00
format.c ALSA: usb-audio: Use standard printk helpers 2014-02-26 16:45:34 +01:00
format.h ALSA: usb-audio: store protocol version in struct audioformat 2013-06-27 21:59:47 +02:00
helper.c ALSA: usb-audio: support wireless devices in snd_usb_parse_datainterval 2013-10-07 12:52:21 +02:00
helper.h
Kconfig ALSA: MIDI driver for Behringer BCD2000 USB device 2014-04-07 16:05:41 +02:00
Makefile ALSA: MIDI driver for Behringer BCD2000 USB device 2014-04-07 16:05:41 +02:00
midi.c sound updates for 3.18-rc1 2014-10-10 22:13:25 -04:00
midi.h ALSA: usb-audio: Whitespace cleanups for sound/usb/midi.* 2014-08-05 20:08:00 +02:00
mixer_maps.c ALSA: usb-audio: work around KEF X300A firmware bug 2014-02-17 10:11:54 +01:00
mixer_quirks.c ALSA: usb-audio: Use standard printk helpers 2014-02-26 16:45:34 +01:00
mixer_quirks.h
mixer.c ALSA: usb-audio: improve dmesg source grepability 2014-08-04 11:18:34 +02:00
mixer.h ALSA: usb-audio: Resume mixer values properly 2014-02-03 09:51:34 +01:00
pcm.c ALSA: usb-audio: Prevent printk ratelimiting from spamming kernel log while DEBUG not defined 2014-05-02 18:10:59 +02:00
pcm.h
power.h
proc.c ALSA: usb-audio: proc: use found syncmaxsize to determine feedback format 2013-05-17 08:05:34 +02:00
proc.h
quirks-table.h ALSA: usb-audio: Add support for Steinberg UR22 USB interface 2014-10-20 07:54:42 +02:00
quirks.c ALSA: usb-audio: add native DSD support for XMOS based DACs 2014-09-08 17:11:39 +02:00
quirks.h ALSA: snd-usb: add quirks handler for DSD streams 2013-04-18 10:03:53 +02:00
stream.c ALSA: usb-audio: Use standard printk helpers 2014-02-26 16:45:34 +01:00
stream.h
usbaudio.h ALSA: usb-audio: Fix deadlocks at resuming 2014-05-02 18:17:06 +02:00