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

[Andrei Simion <andrei.simion@xxxxxxxxxxxxx>]

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.

Fixes: 50291652af52 ("ASoC: atmel: mchp-pdmc: add PDMC driver")
Signed-off-by: Andrei Simion <andrei.simion@xxxxxxxxxxxxx>
---
 sound/soc/atmel/mchp-pdmc.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/sound/soc/atmel/mchp-pdmc.c b/sound/soc/atmel/mchp-pdmc.c
index 939cd44ebc8a..06dc3c48e7e8 100644
--- a/sound/soc/atmel/mchp-pdmc.c
+++ 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 */
+
 	map = mchp_pdmc_chmap_get(substream, info);
 	if (!map)
 		return -EINVAL;

base-commit: 4d0326b60bb753627437fff0f76bf1525bcda422
-- 
2.34.1