From: Haibo Chen haibo.chen@nxp.com
[ Upstream commit 518e26f11af2fe4f5bebf9a0351595d508c7077f ]
The regcache sync will set the cache_bypass = true, at that time, when there is regmap write operation, it will bypass the regmap cache, then the regcache sync will write back the value from cache to register, which is not as our expectation.
Though regmap already use its internal lock to avoid such issue, but this driver force disable the regmap internal lock in its regmap config: disable_locking = true
To avoid this issue, use the driver's own lock to do the protect in system PM.
Fixes: b76574300504 ("gpio: pca953x: Restore registers after suspend/resume cycle") Signed-off-by: Haibo Chen haibo.chen@nxp.com Signed-off-by: Bartosz Golaszewski brgl@bgdev.pl Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/gpio/gpio-pca953x.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-)
diff --git a/drivers/gpio/gpio-pca953x.c b/drivers/gpio/gpio-pca953x.c index 64befd6f702b2..4860bf3b7e002 100644 --- a/drivers/gpio/gpio-pca953x.c +++ b/drivers/gpio/gpio-pca953x.c @@ -1163,7 +1163,9 @@ static int pca953x_suspend(struct device *dev) { struct pca953x_chip *chip = dev_get_drvdata(dev);
+ mutex_lock(&chip->i2c_lock); regcache_cache_only(chip->regmap, true); + mutex_unlock(&chip->i2c_lock);
if (atomic_read(&chip->wakeup_path)) device_set_wakeup_path(dev); @@ -1186,13 +1188,17 @@ static int pca953x_resume(struct device *dev) } }
+ mutex_lock(&chip->i2c_lock); regcache_cache_only(chip->regmap, false); regcache_mark_dirty(chip->regmap); ret = pca953x_regcache_sync(dev); - if (ret) + if (ret) { + mutex_unlock(&chip->i2c_lock); return ret; + }
ret = regcache_sync(chip->regmap); + mutex_unlock(&chip->i2c_lock); if (ret) { dev_err(dev, "Failed to restore register map: %d\n", ret); return ret;