Commit 712a8038 authored Jan 27, 2016 by Lars-Peter Clausen Committed by Mark Brown Jan 27, 2016

ASoC: ssm4567: Reset device before regcache_sync()



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: 1ee44ce0 ("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>
Signed-off-by: Mark Brown <broonie@kernel.org>

parent 92e963f5

sound/soc/codecs/ssm4567.c

+5 −0

Original line number	Diff line number	Diff line
		@@ -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);