Messages in this thread | | | From | "Rafael J. Wysocki" <> | Date | Fri, 25 Jun 2021 19:45:14 +0200 | Subject | Re: [PATCH -next] pwm: img: Fix PM reference leak in img_pwm_enable() |
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On Wed, May 12, 2021 at 6:52 AM Uwe Kleine-König <u.kleine-koenig@pengutronix.de> wrote: > > Hello, > > On Wed, May 12, 2021 at 11:57:17AM +0800, Zou Wei wrote: > > 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 <hulkci@huawei.com> > > Signed-off-by: Zou Wei <zou_wei@huawei.com> > > --- > > 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.
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