On Tue, 12 Jul 2022 12:58:09 +0200, Cezary Rojewski wrote: > > 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. Do we see a similar crash with the hdac-hda stuff, too? And, after avs_hdaudio_driver_exit() is called, why the codec object still remains bound with the HD-audio (Realtek or whatever) codec driver? > 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. Admittedly, the plumbing work for ASoC HD-audio was somewhat messy, and it's fine if we can clean things up. snd_hda_codec_cleanup_for_unbind() is certainly written for unbinding the codec driver, and if a part of that function code is needed for different purposes, it should be factored out properly, at least. thanks, Takashi
