[PATCH 0/3] ASoC: hdac_hda: Fix module unbind/bind via sysfs

[Peter Ujfalusi <peter.ujfalusi@linux.intel.com>]

Hi,

While looking at the reconfig lockup reported in
https://bugzilla.kernel.org/show_bug.cgi?id=222182
I checked whether the same can be done by unbinding and binding the HDA
codec driver via sysfs:

  echo -n ehdaudio0D0 > /sys/bus/hdaudio/drivers/snd_hda_codec_alc882/unbind
  echo -n ehdaudio0D0 > /sys/bus/hdaudio/drivers/snd_hda_codec_alc882/bind

The unbind works and the SOF card is removed, but the codec cannot be
bound again. This has been broken for a long time with hdac_hda; the
reconfig lockup itself is addressed by a separate patch.

Patch 1 and 2 fix the bind: the codec private data was lost on unbind
and the codec device type was left as HDA_DEV_ASOC, so no HDA codec
driver could match it anymore. Patch 2 depends on patch 1, otherwise
the bind would dereference NULL drvdata instead of failing.

Patch 3 fixes an unbalanced runtime PM disable in the component remove,
which leaves the codec with runtime PM disabled after the card is
re-created. This is also visible with machine driver unbind/bind.

Tested on PTL (ALC888 + iDisp): repeated codec and machine driver
unbind/bind, playback/capture, runtime suspend and module reload.

Regards,
Peter
---
Peter Ujfalusi (3):
  ASoC: hdac_hda: Allocate the private data at codec driver bind
  ASoC: hdac_hda: Restore the codec device type on unbind
  ASoC: hdac_hda: Balance the runtime PM disable in codec remove

 sound/soc/codecs/hdac_hda.c     | 29 ++++++++++++++++++++++++++++-
 sound/soc/sof/intel/hda-codec.c | 23 ++++-------------------
 2 files changed, 32 insertions(+), 20 deletions(-)

-- 
2.56.0