When the ssm4567 is powered up the driver calles regcache_sync() to restore the register map content. regcache_sync() assumes that the device is in its power-on reset state. Make sure that this is the case by explicitly resetting the ssm4567 register map before calling regcache_sync() otherwise we might end up with a incorrect register map which leads to undefined behaviour.
One such undefined behaviour was observed when returning from system suspend while a playback stream is active, in that case the ssm4567 was kept muted after resume.
Fixes: 1ee44ce03011 ("ASoC: ssm4567: Add driver for Analog Devices SSM4567 amplifier") Reported-by: Harsha Priya harshapriya.n@intel.com Tested-by: Fang, Yang A yang.a.fang@intel.com Signed-off-by: Lars-Peter Clausen lars@metafoo.de --- sound/soc/codecs/ssm4567.c | 5 +++++ 1 file changed, 5 insertions(+)
diff --git a/sound/soc/codecs/ssm4567.c b/sound/soc/codecs/ssm4567.c index e619d56..080c78e 100644 --- a/sound/soc/codecs/ssm4567.c +++ b/sound/soc/codecs/ssm4567.c @@ -352,6 +352,11 @@ static int ssm4567_set_power(struct ssm4567 *ssm4567, bool enable) regcache_cache_only(ssm4567->regmap, !enable);
if (enable) { + ret = regmap_write(ssm4567->regmap, SSM4567_REG_SOFT_RESET, + 0x00); + if (ret) + return ret; + ret = regmap_update_bits(ssm4567->regmap, SSM4567_REG_POWER_CTRL, SSM4567_POWER_SPWDN, 0x00);