Hi Geert > > Current ALSA SoC Sound Card basically consists of CPU/Codec/Platform > > drivers. If system uses Kernel modules, we can disable these drivers > > by using rmmod command. In such case, we can't disable > > CPU/Codec/Platform driver without disabling Sound Card driver. > > > > But on the other hand, we can disable these drivers by using unbind > > command. In such case, we can disable these drivers randomly. > > In this case, we can create dirty Sound Card which is missing necessary > > components. > > > > (1) If user disabled Sound Card first, but did nothing to other drivers, > > user can't use Sound because Sound Card is no longer exists. > > (2) If user disabled CPU/Codec/Platform driver randomly, but did nothing > > to Sound Card, user still be able to use Sound Card, because dirty Sound > > Card which is missing necessary components still exists. > > In this case, Sound system will be crashed if user started sound > > playback/capture. But we can't block such random unbind now. > > > > To avoid Sound Card crash in (2) case, what we can do now is, add dirty > > flag on Sound Card, and avoid to open Sound Card. > > This patch solved this issue. > > > > Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@xxxxxxxxxxx> > > > --- a/sound/soc/soc-core.c > > +++ b/sound/soc/soc-core.c > > > @@ -3236,6 +3244,8 @@ static void snd_soc_component_cleanup(struct snd_soc_component *component) > > > > static void snd_soc_component_del_unlocked(struct snd_soc_component *component) > > { > > + if (component->card) > > + component->card->dirty = 1; > > Currently this is the only assignment to .dirty. > Can this be undone later, when the driver is bound again? Does this "undone" mean "card->dirty = 0" ? Card itself will be freed if Card was unbind. Thus, card will be re-created if it was bind again. .dirty will be automatically 0 cleared. Best regards --- Kuninori Morimoto _______________________________________________ Alsa-devel mailing list Alsa-devel@xxxxxxxxxxxxxxxx http://mailman.alsa-project.org/mailman/listinfo/alsa-devel