On 2022-07-12 12:46 PM, Takashi Iwai wrote:
On Tue, 12 Jul 2022 11:42:56 +0200,
Cezary Rojewski wrote:
...
snd_hda_codec_cleanup_for_unbind() is called in more places than just
HDAudio codec driver's probe() and remove(). It's also called whenever
HDAudio codec soc-component is being removed. Relevant part of the
stack showing when does the cleanup function get called during rmmod:
[ 220.549349] snd_hda_codec_cleanup_for_unbind+0x25/0x451 [snd_hda_codec]
[ 220.549536] ? dump_stack_lvl+0x45/0x49
[ 220.549568] hda_codec_remove.cold+0x14/0x138 [snd_soc_hda_codec]
[ 220.549609] snd_soc_component_remove+0x34/0x40 [snd_soc_core]
[ 220.549942] soc_remove_component+0x113/0x120 [snd_soc_core]
[ 220.550249] soc_cleanup_card_resources+0x1a7/0x4a0 [snd_soc_core]
[ 220.550561] snd_soc_unbind_card+0x9e/0x190 [snd_soc_core]
[ 220.550885] snd_soc_unregister_card+0x28/0x80 [snd_soc_core]
[ 220.551193] devm_card_release+0x1d/0x20 [snd_soc_core]
[ 220.551527] release_nodes+0x73/0x170
[ 220.551549] ? preempt_count_sub+0x18/0xc0
[ 220.551576] devres_release_all+0x10a/0x150
[ 220.551600] ? devres_remove_group+0x260/0x260
[ 220.551630] device_unbind_cleanup+0x14/0xd0
[ 220.551656] device_release_driver_internal+0x146/0x1d0
[ 220.551688] driver_detach+0x81/0xf0
[ 220.551716] bus_remove_driver+0xae/0x170
[ 220.551743] driver_unregister+0x4d/0x70
[ 220.551770] platform_driver_unregister+0x12/0x20
[ 220.551799] avs_hdaudio_driver_exit+0x10/0x12 [snd_soc_avs_hdaudio]
So, IMO, you're scratching a wrong surface. The problem is rather
that snd_hda_codec_cleanup_for_unbind() is called even if it's not for
unbinding the codec.
This is how ASoC HDAudio codec component was behaving for years, see
sound/soc/codecs/hdac_hda.c. If the intention is _not_ do call
snd_hda_codec_cleanup_for_unbind() then the teardown procedure will
probably need a little update. Actually.. I'm afraid the init one would
need an update to. Given how the implementation of HDAudio codec
component's probe() and remove() looks like, there is no dropping the
cleanup function without changing the upward path accordingly.
Well, to be honest the init/free procedures of HDAudio codec are a
little hairy, perhaps it's time to address this.
Regards,
Czarek
