Messages in this thread | | | Date | Wed, 12 May 2021 06:52:22 +0200 | From | Uwe Kleine-König <> | Subject | Re: [PATCH -next] pwm: img: Fix PM reference leak in img_pwm_enable() |
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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()?
Best regards Uwe
-- Pengutronix e.K. | Uwe Kleine-König | Industrial Linux Solutions | https://www.pengutronix.de/ | [unhandled content-type:application/pgp-signature] | |