regmap: sdw: use _no_pm functions in regmap_read/write
authorBard Liao <yung-chuan.liao@linux.intel.com>
Fri, 22 Jan 2021 07:06:30 +0000 (15:06 +0800)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Thu, 4 Mar 2021 10:38:15 +0000 (11:38 +0100)
commitbf672140d60bd74fb3faf538bccf8eb6adae97e5
treec5920e6c276500f821a216c8f33f6113d935cc7b
parent291803ee73196aceffd2005505f81cf81c16ee38
regmap: sdw: use _no_pm functions in regmap_read/write

[ Upstream commit d288a5712ef961e16d588bbdb2d846e00b5ef154 ]

sdw_update_slave_status will be invoked when a codec is attached,
and the codec driver will initialize the codec with regmap functions
while the codec device is pm_runtime suspended.

regmap routines currently rely on regular SoundWire IO functions,
which will call pm_runtime_get_sync()/put_autosuspend.

This causes a deadlock where the resume routine waits for an
initialization complete signal that while the initialization complete
can only be reached when the resume completes.

The only solution if we allow regmap functions to be used in resume
operations as well as during codec initialization is to use _no_pm
routines. The duty of making sure the bus is operational needs to be
handled above the regmap level.

Fixes: 7c22ce6e21840 ('regmap: Add SoundWire bus support')
Signed-off-by: Bard Liao <yung-chuan.liao@linux.intel.com>
Acked-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20210122070634.12825-6-yung-chuan.liao@linux.intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
drivers/base/regmap/regmap-sdw.c