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  1. 26 8月, 2015 1 次提交
    • T
      ALSA: usb-audio: Avoid nested autoresume calls · 47ab1545
      由 Takashi Iwai 提交于 
      After the recent fix of runtime PM for USB-audio driver, we got a
lockdep warning like:

  =============================================
  [ INFO: possible recursive locking detected ]
  4.2.0-rc8+ #61 Not tainted
  ---------------------------------------------
  pulseaudio/980 is trying to acquire lock:
   (&chip->shutdown_rwsem){.+.+.+}, at: [<ffffffffa0355dac>] snd_usb_autoresume+0x1d/0x52 [snd_usb_audio]
  but task is already holding lock:
   (&chip->shutdown_rwsem){.+.+.+}, at: [<ffffffffa0355dac>] snd_usb_autoresume+0x1d/0x52 [snd_usb_audio]

This comes from snd_usb_autoresume() invoking down_read() and it's
used in a nested way.  Although it's basically safe, per se (as these
are read locks), it's better to reduce such spurious warnings.

The read lock is needed to guarantee the execution of "shutdown"
(cleanup at disconnection) task after all concurrent tasks are
finished.  This can be implemented in another better way.

Also, the current check of chip->in_pm isn't good enough for
protecting the racy execution of multiple auto-resumes.

This patch rewrites the logic of snd_usb_autoresume() & co; namely,
- The recursive call of autopm is avoided by the new refcount,
  chip->active.  The chip->in_pm flag is removed accordingly.
- Instead of rwsem, another refcount, chip->usage_count, is introduced
  for tracking the period to delay the shutdown procedure.  At
  the last clear of this refcount, wake_up() to the shutdown waiter is
  called.
- The shutdown flag is replaced with shutdown atomic count; this is
  for reducing the lock.
- Two new helpers are introduced to simplify the management of these
  refcounts; snd_usb_lock_shutdown() increases the usage_count, checks
  the shutdown state, and does autoresume.  snd_usb_unlock_shutdown()
  does the opposite.  Most of mixer and other codes just need this,
  and simply returns an error if it receives an error from lock.

Fixes: 9003ebb1 ('ALSA: usb-audio: Fix runtime PM unbalance')
Reported-and-tested-by: NAlexnader Kuleshov <kuleshovmail@gmail.com>
Signed-off-by: NTakashi Iwai <tiwai@suse.de>
      47ab1545
  3. 20 8月, 2015 1 次提交
  5. 14 8月, 2015 1 次提交
  7. 11 6月, 2015 1 次提交
  9. 03 6月, 2015 1 次提交
  11. 29 5月, 2015 1 次提交
  13. 18 1月, 2015 1 次提交
  15. 21 11月, 2014 2 次提交
    • T
      ALSA: usb-audio: Allow quirks to handle own resume and proc dump · 3360b84b
      由 Takashi Iwai 提交于 
      So far, we blindly assumed that the all usb-audio mixer elements
follow the standard and apply the standard resume method for the
registered elements in the id_elems[] list.  However, some quirks
really need the own resume and it's incomplete for now.

This patch enhances the resume handling in two folds:
- split some fields in struct usb_mixer_elem_info into a smaller
  header struct (usb_mixer_elem_list) for keeping the minimal
  information in the linked-list; the usb_mixer_elem_info embeds this
  header struct instead
- add resume and dump callbacks to usb_mixer_elem_list struct to allow
  quirks providing the own methods

For the standard mixer elements, these new callbacks are set to the
standard ones as default, thus there is no functional change by this
patch yet.

The dump and resume callbacks are typedef'ed for ease of later patches
using arrays of such function pointers.
Signed-off-by: NTakashi Iwai <tiwai@suse.de>
      3360b84b
    • T
      ALSA: usb-audio: Refactor ignore_ctl_error checks · 5aeee342
      由 Takashi Iwai 提交于 
      Introduce an internal helper macro for avoiding many open codes.

The only slight behavior change is in a couple of get ballcks where
the value is reset at error no matter whether ignore_ctl_error is set
or not.  Actually this is even safer than before.
Signed-off-by: NTakashi Iwai <tiwai@suse.de>
      5aeee342
  17. 17 11月, 2014 1 次提交
  19. 13 11月, 2014 1 次提交
  21. 04 11月, 2014 1 次提交
  23. 19 10月, 2014 1 次提交
  25. 04 8月, 2014 1 次提交
  27. 25 5月, 2014 2 次提交
  29. 28 4月, 2014 1 次提交
  31. 05 3月, 2014 1 次提交
  33. 26 2月, 2014 1 次提交
    • T
      ALSA: usb-audio: Use standard printk helpers · 0ba41d91
      由 Takashi Iwai 提交于 
      Convert with dev_err() and co from snd_printk(), etc.
As there are too deep indirections (e.g. ep->chip->dev->dev),
a few new local macros, usb_audio_err() & co, are introduced.

Also, the device numbers in some messages are dropped, as they are
shown in the prefix automatically.
Signed-off-by: NTakashi Iwai <tiwai@suse.de>
      0ba41d91
  35. 14 2月, 2014 1 次提交
  37. 03 2月, 2014 1 次提交
  39. 26 9月, 2013 1 次提交
  41. 12 8月, 2013 1 次提交
  43. 17 6月, 2013 1 次提交
  45. 05 6月, 2013 1 次提交
  47. 20 3月, 2013 3 次提交
  49. 11 2月, 2013 1 次提交
  51. 27 1月, 2013 1 次提交
  53. 29 11月, 2012 4 次提交
  55. 30 10月, 2012 2 次提交
    • T
      ALSA: usb-audio: Use rwsem for disconnect protection · 34f3c89f
      由 Takashi Iwai 提交于 
      Replace mutex with rwsem for codec->shutdown protection so that
concurrent accesses are allowed.

Also add the protection to snd_usb_autosuspend() and
snd_usb_autoresume(), too.
Reported-by: NMatthieu CASTET <matthieu.castet@parrot.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: NTakashi Iwai <tiwai@suse.de>
      34f3c89f
    • T
      ALSA: usb-audio: Fix races at disconnection · 978520b7
      由 Takashi Iwai 提交于 
      Close some races at disconnection of a USB audio device by adding the
chip->shutdown_mutex and chip->shutdown check at appropriate places.

The spots to put bandaids are:
- PCM prepare, hw_params and hw_free
- where the usb device is accessed for communication or get speed, in
 mixer.c and others; the device speed is now cached in subs->speed
 instead of accessing to chip->dev

The accesses in PCM open and close don't need the mutex protection
because these are already handled in the core PCM disconnection code.

The autosuspend/autoresume codes are still uncovered by this patch
because of possible mutex deadlocks.  They'll be covered by the
upcoming change to rwsem.

Also the mixer codes are untouched, too.  These will be fixed in
another patch, too.
Reported-by: NMatthieu CASTET <matthieu.castet@parrot.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: NTakashi Iwai <tiwai@suse.de>
      978520b7
  57. 20 9月, 2012 1 次提交
  59. 15 5月, 2012 1 次提交
  61. 24 4月, 2012 2 次提交