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gpio: pca953x: Add mutex_lock for regcache sync in PM

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[ Upstream commit 518e26f11a ]

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: b765743005 ("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>
This commit is contained in:
Haibo Chen 2022-08-31 18:37:35 +08:00 committed by Greg Kroah-Hartman
parent 7756eb1ed1
commit cb2684e906
1 changed files with 7 additions and 1 deletions
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8
drivers/gpio/gpio-pca953x.c
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@ -1198,7 +1198,9 @@ 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);
@ -1221,13 +1223,17 @@ 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;