ASoC: ssm4567: Reset device before regcache_sync()
authorLars-Peter Clausen <lars@metafoo.de>
Wed, 27 Jan 2016 13:26:18 +0000 (14:26 +0100)
committerSasha Levin <sasha.levin@oracle.com>
Mon, 11 Jul 2016 03:07:11 +0000 (23:07 -0400)
commitfad61c46cc9c999169b95d14a67c60a0a7141d00
treee245656066f9191fdba97506a576ac408db481d6
parent0cbc7967e970b92f2b60a5d935dc49eef08cfa2e
ASoC: ssm4567: Reset device before regcache_sync()

[ Upstream commit 712a8038cc24dba668afe82f0413714ca87184e0 ]

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>
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
sound/soc/codecs/ssm4567.c