Hello Zou,
On Mon, Jun 28, 2021 at 08:38:39AM +0200, Uwe Kleine-König wrote:

On Fri, Jun 25, 2021 at 07:45:14PM +0200, Rafael J. Wysocki wrote:

quoted

On Wed, May 12, 2021 at 6:52 AM Uwe Kleine-König
[off-list ref] wrote:

quoted

On Wed, May 12, 2021 at 11:57:17AM +0800, Zou Wei wrote:

quoted

pm_runtime_get_sync will increment pm usage counter even it failed.
Forgetting to putting operation will result in reference leak here.
Fix it by replacing it with pm_runtime_resume_and_get to keep usage
counter balanced.

Reported-by: Hulk Robot <redacted>
Signed-off-by: Zou Wei <redacted>
---
 drivers/pwm/pwm-img.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/pwm/pwm-img.c b/drivers/pwm/pwm-img.c
index cc37054..11b16ec 100644
--- a/drivers/pwm/pwm-img.c
+++ b/drivers/pwm/pwm-img.c

@@ -156,7 +156,7 @@ static int img_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm)
      struct img_pwm_chip *pwm_chip = to_img_pwm_chip(chip);
      int ret;

-     ret = pm_runtime_get_sync(chip->dev);
+     ret = pm_runtime_resume_and_get(chip->dev);
      if (ret < 0)
              return ret;

This patch looks right with my limited understanding of pm_runtime. A
similar issue in this driver was fixed in commit

        ca162ce98110 ("pwm: img: Call pm_runtime_put() in pm_runtime_get_sync() failed case")

where (even though the commit log talks about pm_runtime_put()) a call
to pm_runtime_put_autosuspend() was added in the error path.

I added the PM guys to Cc, maybe they can advise about the right thing
to do here. Does it make sense to use the same idiom in both
img_pwm_enable() and img_pwm_config()?

I think so.

And calling pm_runtime_put_autosuspend() in the img_pwm_enable() error
path would work too.

Do you care to clean this up accordingly and send a new patch?

Note that Thierry applied your initial patch regardless of the
inconsistency. Still I'd like to see this done in a consistent way. Do
you care to follow up with a patch that unifies the behaviour?

Best regards
Uwe

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Pengutronix e.K.                           | Uwe Kleine-König            |
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