[PATCH] drm/bridge: display-connector: fix i2c adapter leak on probe failure

[PATCH] drm/bridge: display-connector: fix i2c adapter leak on probe failure

[Johan Hovold]

Make sure to drop the i2c adapter device and module references on failed
regulator and enable gpio lookup (and regulator enable) during probe
(e.g. on probe deferral).

Note that of_get_i2c_adapter_by_node() does not return error pointers,
but i2c_put_adapter() can handle a NULL argument so the error pointer
check at remove works even if it is misleading.

Fixes: 2e2bf3a5584d ("drm/bridge: display-connector: add DP support")
Fixes: 6de79dd3a920 ("drm/bridge: display-connector: add ddc-en gpio support")
Fixes: 6eb6b6f0a012 ("drm/bridge: display-connector: handle hdmi-pwr supply")
Cc: stable@vger.kernel.org	# 5.12
Cc: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
Cc: H. Nikolaus Schaller <hns@goldelico.com>
Cc: Dmitry Baryshkov <lumag@kernel.org>
Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Johan Hovold <johan@kernel.org>
---
 drivers/gpu/drm/bridge/display-connector.c | 16 +++++++++++++---
 1 file changed, 13 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/bridge/display-connector.c b/drivers/gpu/drm/bridge/display-connector.c
index 16c0631adeb1..c38de5518211 100644
--- a/drivers/gpu/drm/bridge/display-connector.c
+++ b/drivers/gpu/drm/bridge/display-connector.c
@@ -208,6 +208,13 @@ static int display_connector_get_supply(struct platform_device *pdev,
 	return PTR_ERR_OR_ZERO(conn->supply);
 }
 
+static void display_connector_put_ddc(void *_ddc)
+{
+	struct i2c_adapter *ddc = _ddc;
+
+	i2c_put_adapter(ddc);
+}
+
 static int display_connector_probe(struct platform_device *pdev)
 {
 	struct display_connector *conn;
@@ -328,6 +335,12 @@ static int display_connector_probe(struct platform_device *pdev)
 			of_node_put(phandle);
 			if (!conn->bridge.ddc)
 				return -EPROBE_DEFER;
+
+			ret = devm_add_action_or_reset(&pdev->dev,
+						       display_connector_put_ddc,
+						       conn->bridge.ddc);
+			if (ret)
+				return ret;
 		} else {
 			dev_dbg(&pdev->dev,
 				"No I2C bus specified, disabling EDID readout\n");
@@ -403,9 +416,6 @@ static void display_connector_remove(struct platform_device *pdev)
 		regulator_disable(conn->supply);
 
 	drm_bridge_remove(&conn->bridge);
-
-	if (!IS_ERR(conn->bridge.ddc))
-		i2c_put_adapter(conn->bridge.ddc);
 }
 
 static const struct of_device_id display_connector_match[] = {
-- 
2.54.0

Re: [PATCH] drm/bridge: display-connector: fix i2c adapter leak on probe failure

[Laurent Pinchart]

Hi Johan,

Thank you for the patch.

On Fri, Jul 17, 2026 at 10:57:16AM +0200, Johan Hovold wrote:
> Make sure to drop the i2c adapter device and module references on failed
> regulator and enable gpio lookup (and regulator enable) during probe
> (e.g. on probe deferral).
> 
> Note that of_get_i2c_adapter_by_node() does not return error pointers,
> but i2c_put_adapter() can handle a NULL argument so the error pointer
> check at remove works even if it is misleading.

I've already sent a fix for this, see

https://lore.kernel.org/dri-devel/20260705213542.28987-3-laurent.pinchart+renesas@ideasonboard.com/

> Fixes: 2e2bf3a5584d ("drm/bridge: display-connector: add DP support")
> Fixes: 6de79dd3a920 ("drm/bridge: display-connector: add ddc-en gpio support")
> Fixes: 6eb6b6f0a012 ("drm/bridge: display-connector: handle hdmi-pwr supply")
> Cc: stable@vger.kernel.org	# 5.12
> Cc: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
> Cc: H. Nikolaus Schaller <hns@goldelico.com>
> Cc: Dmitry Baryshkov <lumag@kernel.org>
> Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
> Signed-off-by: Johan Hovold <johan@kernel.org>
> ---
>  drivers/gpu/drm/bridge/display-connector.c | 16 +++++++++++++---
>  1 file changed, 13 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/gpu/drm/bridge/display-connector.c b/drivers/gpu/drm/bridge/display-connector.c
> index 16c0631adeb1..c38de5518211 100644
> --- a/drivers/gpu/drm/bridge/display-connector.c
> +++ b/drivers/gpu/drm/bridge/display-connector.c
> @@ -208,6 +208,13 @@ static int display_connector_get_supply(struct platform_device *pdev,
>  	return PTR_ERR_OR_ZERO(conn->supply);
>  }
>  
> +static void display_connector_put_ddc(void *_ddc)
> +{
> +	struct i2c_adapter *ddc = _ddc;
> +
> +	i2c_put_adapter(ddc);
> +}
> +
>  static int display_connector_probe(struct platform_device *pdev)
>  {
>  	struct display_connector *conn;
> @@ -328,6 +335,12 @@ static int display_connector_probe(struct platform_device *pdev)
>  			of_node_put(phandle);
>  			if (!conn->bridge.ddc)
>  				return -EPROBE_DEFER;
> +
> +			ret = devm_add_action_or_reset(&pdev->dev,
> +						       display_connector_put_ddc,
> +						       conn->bridge.ddc);
> +			if (ret)
> +				return ret;
>  		} else {
>  			dev_dbg(&pdev->dev,
>  				"No I2C bus specified, disabling EDID readout\n");
> @@ -403,9 +416,6 @@ static void display_connector_remove(struct platform_device *pdev)
>  		regulator_disable(conn->supply);
>  
>  	drm_bridge_remove(&conn->bridge);
> -
> -	if (!IS_ERR(conn->bridge.ddc))
> -		i2c_put_adapter(conn->bridge.ddc);
>  }
>  
>  static const struct of_device_id display_connector_match[] = {

-- 
Regards,

Laurent Pinchart

Re: [PATCH] drm/bridge: display-connector: fix i2c adapter leak on probe failure

[Johan Hovold]

On Fri, Jul 17, 2026 at 03:20:35PM +0300, Laurent Pinchart wrote:

> On Fri, Jul 17, 2026 at 10:57:16AM +0200, Johan Hovold wrote:
> > Make sure to drop the i2c adapter device and module references on failed
> > regulator and enable gpio lookup (and regulator enable) during probe
> > (e.g. on probe deferral).
> > 
> > Note that of_get_i2c_adapter_by_node() does not return error pointers,
> > but i2c_put_adapter() can handle a NULL argument so the error pointer
> > check at remove works even if it is misleading.
> 
> I've already sent a fix for this, see
> 
> https://lore.kernel.org/dri-devel/20260705213542.28987-3-laurent.pinchart+renesas@ideasonboard.com/

Ah, ok. If that series is blocked perhaps you can send the fix
separately.

Johan