The normal PCM operations are already blocked during the card power
off state in the PCM common ioctl handler, but the release isn't
covered. As the PCM stream release may also access the hardware,
let's block the release until the card power turns on.
Reviewed-by: Jaroslav Kysela <perex@perex.cz>
Link: https://lore.kernel.org/r/20210523090920.15345-7-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>
if (snd_BUG_ON(!substream))
return -ENXIO;
pcm = substream->pcm;
+
+ /* block until the device gets woken up as it may touch the hardware */
+ snd_power_wait(pcm->card);
+
mutex_lock(&pcm->open_mutex);
snd_pcm_release_substream(substream);
kfree(pcm_file);