Messages in this thread | | | Date | Mon, 28 Jun 2021 19:01:05 +0200 | From | Uwe Kleine-König <> | Subject | Re: [PATCH -next] pwm: img: Fix PM reference leak in img_pwm_enable() |
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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: > > On Wed, May 12, 2021 at 6:52 AM Uwe Kleine-König > > <u.kleine-koenig@pengutronix.de> wrote: > > > 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. > > 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
-- Pengutronix e.K. | Uwe Kleine-König | Industrial Linux Solutions | https://www.pengutronix.de/ | [unhandled content-type:application/pgp-signature] | |