[PATCH v3 0/2] ALSA: core: Fix deadlock when shutdown a frozen userspace

[Ricardo Ribalda]

Since 83bfc7e793b5 ("ASoC: SOF: core: unregister clients and machine drivers in .shutdown")
we wait for userspace to close its fds.

But that will never occur with a frozen userspace (like during kexec()).

Lets detect the frozen userpace and act accordingly.

To: Jaroslav Kysela <perex at perex.cz>
To: Takashi Iwai <tiwai at suse.com>
To: "Rafael J. Wysocki" <rafael at kernel.org>
To: Pavel Machek <pavel at ucw.cz>
To: Len Brown <len.brown at intel.com>
To: Kai Vehmanen <kai.vehmanen at linux.intel.com>
To: Ranjani Sridharan <ranjani.sridharan at linux.intel.com>
To: Pierre-Louis Bossart <pierre-louis.bossart at linux.intel.com>
To: Mark Brown <broonie at kernel.org>
Cc: alsa-devel at alsa-project.org
Cc: linux-kernel at vger.kernel.org
Cc: "Joel Fernandes (Google)" <joel at joelfernandes.org>
Cc: linux-pm at vger.kernel.org
Signed-off-by: Ricardo Ribalda <ribalda at chromium.org>
---
Changes in v3:
- Wrap pm_freezing in a function
- Link to v2: https://lore.kernel.org/r/20221127-snd-freeze-v2-0-d8a425ea9663@chromium.org

Changes in v2:
- Only use pm_freezing if CONFIG_FREEZER 
- Link to v1: https://lore.kernel.org/r/20221127-snd-freeze-v1-0-57461a366ec2@chromium.org

---
Ricardo Ribalda (2):
      freezer: Add processes_frozen()
      ALSA: core: Fix deadlock when shutdown a frozen userspace

 include/linux/freezer.h |  2 ++
 kernel/freezer.c        | 11 +++++++++++
 sound/core/init.c       | 13 +++++++++++++
 3 files changed, 26 insertions(+)
---
base-commit: 4312098baf37ee17a8350725e6e0d0e8590252d4
change-id: 20221127-snd-freeze-1ee143228326

Best regards,
-- 
Ricardo Ribalda <ribalda at chromium.org>