[PATCH v2 1/2] drm/panel-edp: fix i2c adapter leak on probe failure

[PATCH v2 1/2] drm/panel-edp: fix i2c adapter leak on probe failure

[Johan Hovold]

Make sure to drop the i2c adapter reference on probe failure (e.g.
probe deferral) and on driver unbind also if a devicetree redundantly
uses the 'ddc-i2c-bus' property to point to the aux ddc bus.

Fixes: cc5a3fc041f0 ("drm/panel: panel-simple: Stash DP AUX bus; allow using it for DDC")
Cc: stable@vger.kernel.org	# 5.15
Reported-by: Douglas Anderson <dianders@chromium.org>
Link: https://lore.kernel.org/r/CAD=FV=VZPhzHU+Pet2m3L+Pqc7mOPfZC-f5p0OuNL79wNZPxRg@mail.gmail.com
Signed-off-by: Johan Hovold <johan@kernel.org>
---
 drivers/gpu/drm/panel/panel-edp.c | 19 +++++++++++++------
 1 file changed, 13 insertions(+), 6 deletions(-)

diff --git a/drivers/gpu/drm/panel/panel-edp.c b/drivers/gpu/drm/panel/panel-edp.c
index aa27d6cd932e..ac815729aa83 100644
--- a/drivers/gpu/drm/panel/panel-edp.c
+++ b/drivers/gpu/drm/panel/panel-edp.c
@@ -831,6 +831,13 @@ static int generic_edp_panel_probe(struct device *dev, struct panel_edp *panel)
 	return 0;
 }
 
+static void panel_edp_put_adapter(void *_adap)
+{
+	struct i2c_adapter *adap = _adap;
+
+	put_device(&adap->dev);
+}
+
 static int panel_edp_probe(struct device *dev, const struct panel_desc *desc,
 			   struct drm_dp_aux *aux)
 {
@@ -878,6 +885,11 @@ static int panel_edp_probe(struct device *dev, const struct panel_desc *desc,
 
 		if (!panel->ddc)
 			return -EPROBE_DEFER;
+
+		err = devm_add_action_or_reset(dev, panel_edp_put_adapter,
+					       panel->ddc);
+		if (err)
+			return err;
 	} else if (aux) {
 		panel->ddc = &aux->ddc;
 	}
@@ -889,7 +901,7 @@ static int panel_edp_probe(struct device *dev, const struct panel_desc *desc,
 
 	err = drm_panel_of_backlight(&panel->base);
 	if (err)
-		goto err_finished_ddc_init;
+		return err;
 
 	/*
 	 * We use runtime PM for prepare / unprepare since those power the panel
@@ -936,9 +948,6 @@ static int panel_edp_probe(struct device *dev, const struct panel_desc *desc,
 err_finished_pm_runtime:
 	pm_runtime_dont_use_autosuspend(dev);
 	pm_runtime_disable(dev);
-err_finished_ddc_init:
-	if (panel->ddc && (!panel->aux || panel->ddc != &panel->aux->ddc))
-		put_device(&panel->ddc->dev);
 
 	return err;
 }
@@ -982,8 +991,6 @@ static void panel_edp_remove(struct device *dev)
 
 	pm_runtime_dont_use_autosuspend(dev);
 	pm_runtime_disable(dev);
-	if (panel->ddc && (!panel->aux || panel->ddc != &panel->aux->ddc))
-		put_device(&panel->ddc->dev);
 
 	drm_edid_free(panel->drm_edid);
 	panel->drm_edid = NULL;
-- 
2.54.0

Re: [PATCH v2 1/2] drm/panel-edp: fix i2c adapter leak on probe failure

[Doug Anderson]

Hi,

On Fri, Jul 17, 2026 at 7:32 AM Johan Hovold <johan@kernel.org> wrote:
>
> Make sure to drop the i2c adapter reference on probe failure (e.g.
> probe deferral) and on driver unbind also if a devicetree redundantly
> uses the 'ddc-i2c-bus' property to point to the aux ddc bus.
>
> Fixes: cc5a3fc041f0 ("drm/panel: panel-simple: Stash DP AUX bus; allow using it for DDC")
> Cc: stable@vger.kernel.org      # 5.15
> Reported-by: Douglas Anderson <dianders@chromium.org>
> Link: https://lore.kernel.org/r/CAD=FV=VZPhzHU+Pet2m3L+Pqc7mOPfZC-f5p0OuNL79wNZPxRg@mail.gmail.com
> Signed-off-by: Johan Hovold <johan@kernel.org>
> ---
>  drivers/gpu/drm/panel/panel-edp.c | 19 +++++++++++++------
>  1 file changed, 13 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/gpu/drm/panel/panel-edp.c b/drivers/gpu/drm/panel/panel-edp.c
> index aa27d6cd932e..ac815729aa83 100644
> --- a/drivers/gpu/drm/panel/panel-edp.c
> +++ b/drivers/gpu/drm/panel/panel-edp.c
> @@ -831,6 +831,13 @@ static int generic_edp_panel_probe(struct device *dev, struct panel_edp *panel)
>         return 0;
>  }
>
> +static void panel_edp_put_adapter(void *_adap)
> +{
> +       struct i2c_adapter *adap = _adap;
> +
> +       put_device(&adap->dev);
> +}
> +
>  static int panel_edp_probe(struct device *dev, const struct panel_desc *desc,
>                            struct drm_dp_aux *aux)
>  {
> @@ -878,6 +885,11 @@ static int panel_edp_probe(struct device *dev, const struct panel_desc *desc,
>
>                 if (!panel->ddc)
>                         return -EPROBE_DEFER;
> +
> +               err = devm_add_action_or_reset(dev, panel_edp_put_adapter,
> +                                              panel->ddc);
> +               if (err)
> +                       return err;

Yeah, devm makes this so much nicer. Thanks for fixing!

Reviewed-by: Douglas Anderson <dianders@chromium.org>

I'll plan to apply this, probably to drm-misc-next next week. Unless
someone objects, I won't land it -fixes because it's such a corner
case.

-Doug

Re: [PATCH v2 1/2] drm/panel-edp: fix i2c adapter leak on probe failure

[Johan Hovold]

On Fri, Jul 17, 2026 at 10:03:42AM -0700, Doug Anderson wrote:

> > @@ -878,6 +885,11 @@ static int panel_edp_probe(struct device *dev, const struct panel_desc *desc,
> >
> >                 if (!panel->ddc)
> >                         return -EPROBE_DEFER;
> > +
> > +               err = devm_add_action_or_reset(dev, panel_edp_put_adapter,
> > +                                              panel->ddc);
> > +               if (err)
> > +                       return err;
> 
> Yeah, devm makes this so much nicer. Thanks for fixing!
> 
> Reviewed-by: Douglas Anderson <dianders@chromium.org>
> 
> I'll plan to apply this, probably to drm-misc-next next week. Unless
> someone objects, I won't land it -fixes because it's such a corner
> case.

Sounds good. Thanks.

Johan

Re: [PATCH v2 1/2] drm/panel-edp: fix i2c adapter leak on probe failure

[Doug Anderson]

Hi,

On Mon, Jul 20, 2026 at 12:46 AM Johan Hovold <johan@kernel.org> wrote:
>
> On Fri, Jul 17, 2026 at 10:03:42AM -0700, Doug Anderson wrote:
>
> > > @@ -878,6 +885,11 @@ static int panel_edp_probe(struct device *dev, const struct panel_desc *desc,
> > >
> > >                 if (!panel->ddc)
> > >                         return -EPROBE_DEFER;
> > > +
> > > +               err = devm_add_action_or_reset(dev, panel_edp_put_adapter,
> > > +                                              panel->ddc);
> > > +               if (err)
> > > +                       return err;
> >
> > Yeah, devm makes this so much nicer. Thanks for fixing!
> >
> > Reviewed-by: Douglas Anderson <dianders@chromium.org>
> >
> > I'll plan to apply this, probably to drm-misc-next next week. Unless
> > someone objects, I won't land it -fixes because it's such a corner
> > case.
>
> Sounds good. Thanks.

Pushed to drm-misc-next:

[1/2] drm/panel-edp: fix i2c adapter leak on probe failure
      commit: e2a9e291275a74e309a21cbb1def6296a72d6aed