Re: [PATCH -next] drm: Fix PM reference leak

[Samuel Zou]

Hi Daniel,

Thanks for your review, I will split the patch and resend.

On 2021/5/21 23:32, Daniel Vetter wrote:
> On Fri, May 21, 2021 at 09:03:06PM +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@xxxxxxxxxx>
> > Signed-off-by: Zou Wei <zou_wei@xxxxxxxxxx>
>
> Looks good, but can you pls split this up into a patch per driver (vc and
> bridge/cdns-dsi here)?
>
> Thanks, Daniel
>
> > ---
> >   drivers/gpu/drm/bridge/cdns-dsi.c | 2 +-
> >   drivers/gpu/drm/vc4/vc4_hdmi.c    | 2 +-
> >   2 files changed, 2 insertions(+), 2 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/bridge/cdns-dsi.c b/drivers/gpu/drm/bridge/cdns-dsi.c
> > index 76373e3..b31281f 100644
> > --- a/drivers/gpu/drm/bridge/cdns-dsi.c
> > +++ b/drivers/gpu/drm/bridge/cdns-dsi.c
> > @@ -1028,7 +1028,7 @@ static ssize_t cdns_dsi_transfer(struct mipi_dsi_host *host,
> >   	struct mipi_dsi_packet packet;
> >   	int ret, i, tx_len, rx_len;
> >   
> > -	ret = pm_runtime_get_sync(host->dev);
> > +	ret = pm_runtime_resume_and_get(host->dev);
> >   	if (ret < 0)
> >   		return ret;
> >   
> > diff --git a/drivers/gpu/drm/vc4/vc4_hdmi.c b/drivers/gpu/drm/vc4/vc4_hdmi.c
> > index c27b287..f20a65b 100644
> > --- a/drivers/gpu/drm/vc4/vc4_hdmi.c
> > +++ b/drivers/gpu/drm/vc4/vc4_hdmi.c
> > @@ -798,7 +798,7 @@ static void vc4_hdmi_encoder_pre_crtc_configure(struct drm_encoder *encoder,
> >   	unsigned long pixel_rate, hsm_rate;
> >   	int ret;
> >   
> > -	ret = pm_runtime_get_sync(&vc4_hdmi->pdev->dev);
> > +	ret = pm_runtime_resume_and_get(&vc4_hdmi->pdev->dev);
> >   	if (ret < 0) {
> >   		DRM_ERROR("Failed to retain power domain: %d\n", ret);
> >   		return;
> > --
> > 2.6.2