From: Haibo Chen haibo.chen@nxp.com
stable inclusion from stable-v5.10.142 commit 7efcbac55aadd83d616361746d8bb1aabc7ffcdb category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/I6CSFH
Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=...
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[ 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 Signed-off-by: Jialin Zhang zhangjialin11@huawei.com Reviewed-by: Zheng Zengkai zhengzengkai@huawei.com --- 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 957be5f69406..3ad1a9e432c8 100644 --- a/drivers/gpio/gpio-pca953x.c +++ b/drivers/gpio/gpio-pca953x.c @@ -1162,7 +1162,9 @@ 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); @@ -1185,13 +1187,17 @@ 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;