[PATCH] ASoC: tlv320aic31xx: Fix jack detection after suspend

[Mark Brown]

The tlv320aic31xx driver relies on regcache_sync() to restore the register
contents after going to _BIAS_OFF, for example during system suspend. This
does not work for the jack detection configuration since that is configured
via the same register that status is read back from so the register is
volatile and not cached. This can also cause issues during init if the jack
detection ends up getting set up before the CODEC is initially brought out
of _BIAS_OFF, we will reset the CODEC and resync the cache as part of that
process.

Fix this by explicitly reapplying the jack detection configuration after
resyncing the register cache during power on.

This issue was found by an engineer working off-list on a product
kernel, I just wrote up the upstream fix.

Signed-off-by: Mark Brown <broonie at kernel.org>
---
 sound/soc/codecs/tlv320aic31xx.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/sound/soc/codecs/tlv320aic31xx.c b/sound/soc/codecs/tlv320aic31xx.c
index b504d63385b3..e3da8f41fd1a 100644
--- a/sound/soc/codecs/tlv320aic31xx.c
+++ b/sound/soc/codecs/tlv320aic31xx.c
@@ -1256,6 +1256,13 @@ static int aic31xx_power_on(struct snd_soc_component *component)
 		return ret;
 	}
 
+	/*
+	 * The jack detection configuration is in the same register
+	 * that is used to report jack detect status so is volatile
+	 * and not covered by the cache sync, restore it separately.
+	 */
+	aic31xx_set_jack(component, aic31xx->jack, NULL);
+
 	return 0;
 }
 
-- 
2.20.1