Re: [PATCH] ASoC: atmel: mchp-pdmc: Skip ALSA restoration if substream runtime is uninitialized

24 Sep 2024


      On Tue, Sep 24, 2024 at 11:12:38AM +0300, Andrei Simion wrote:
...
Update the driver to prevent alsa-restore.service from failing when
reading data from /var/lib/alsa/asound.state at boot. Ensure that the
restoration of ALSA mixer configurations is skipped if substream->runtime
is NULL.
...
+++ b/sound/soc/atmel/mchp-pdmc.c
@@ -302,6 +302,9 @@ static int mchp_pdmc_chmap_ctl_put(struct snd_kcontrol *kcontrol,
   if (!substream)
   	return -ENODEV;

if (!substream->runtime)
return 0; /* just for avoiding error from alsactl restore */




This then means that control writes are just discarded which presumably
is going to upset things if they actually saved a value here.  Why is
that a good choice, rather than either fixing the race so the card
doesn't come up too early or removing the need for the runtime?

    

Mark Brown