This is a note to let you know that I've just added the patch titled regmap: sdw: use _no_pm functions in regmap_read/write to the 5.4-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: regmap-sdw-use-_no_pm-functions-in-regmap_read-write.patch and it can be found in the queue-5.4 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit d51dfad5590bdcd0d8f4aa5355185d240d62505b Author: Bard Liao <yung-chuan.liao@xxxxxxxxxxxxxxx> Date: Fri Jan 22 15:06:30 2021 +0800 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@xxxxxxxxxxxxxxx> Acked-by: Mark Brown <broonie@xxxxxxxxxx> Link: https://lore.kernel.org/r/20210122070634.12825-6-yung-chuan.liao@xxxxxxxxxxxxxxx Signed-off-by: Vinod Koul <vkoul@xxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/drivers/base/regmap/regmap-sdw.c b/drivers/base/regmap/regmap-sdw.c index 50a66382d87d0..e75168b941d0c 100644 --- a/drivers/base/regmap/regmap-sdw.c +++ b/drivers/base/regmap/regmap-sdw.c @@ -12,7 +12,7 @@ static int regmap_sdw_write(void *context, unsigned int reg, unsigned int val) struct device *dev = context; struct sdw_slave *slave = dev_to_sdw_dev(dev); - return sdw_write(slave, reg, val); + return sdw_write_no_pm(slave, reg, val); } static int regmap_sdw_read(void *context, unsigned int reg, unsigned int *val) @@ -21,7 +21,7 @@ static int regmap_sdw_read(void *context, unsigned int reg, unsigned int *val) struct sdw_slave *slave = dev_to_sdw_dev(dev); int read; - read = sdw_read(slave, reg); + read = sdw_read_no_pm(slave, reg); if (read < 0) return read;