From: Michael Walle michael@walle.cc

[ Upstream commit e9149b8c00d25dbaef1aa174fc604bed207e576d ]

The current code assumes that the power is turned off in SND_SOC_BIAS_OFF. If there are no actual regulator the codec isn't turned off and the registers are not reset to their default values but the regcache is still marked as dirty. Thus a value might not be written to the hardware if it is set to the default value. Do a software reset before turning off the power to make sure the registers are always reset to their default states.

Signed-off-by: Michael Walle michael@walle.cc Acked-by: Charles Keepax ckeepax@opensource.cirrus.com Link: https://lore.kernel.org/r/20191112223629.21867-1-michael@walle.cc Signed-off-by: Mark Brown broonie@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- sound/soc/codecs/wm8904.c | 1 + 1 file changed, 1 insertion(+)

diff --git a/sound/soc/codecs/wm8904.c b/sound/soc/codecs/wm8904.c index 1965635ec07c7..d14e851b91605 100644 --- a/sound/soc/codecs/wm8904.c +++ b/sound/soc/codecs/wm8904.c @@ -1902,6 +1902,7 @@ static int wm8904_set_bias_level(struct snd_soc_component *component, snd_soc_component_update_bits(component, WM8904_BIAS_CONTROL_0, WM8904_BIAS_ENA, 0);

+ snd_soc_component_write(component, WM8904_SW_RESET_AND_ID, 0); regcache_cache_only(wm8904->regmap, true); regcache_mark_dirty(wm8904->regmap);