[PATCH 05/10] drm/bridge: lontium-lt9611uxc: switch to of_drm_get_bridge_by_endpoint()

[Dmitry Baryshkov]

On Mon, Apr 13, 2026 at 03:58:37PM +0200, Luca Ceresoli wrote:
> This driver calls drm_of_find_panel_or_bridge() with a NULL pointer in the
> @panel parameter, thus using a reduced feature set of that function.
> Replace this call with the simpler of_drm_get_bridge_by_endpoint().
> 
> Since of_drm_get_bridge_by_endpoint() increases the refcount of the
> returned bridge, ensure it is put on removal. To achieve this, instead of
> adding an explicit drm_bridge_put(), migrate to the bridge::next_bridge
> pointer which is automatically put when the bridge is eventually freed.

What if the driver's _probe fails between increasing this refcount and
actually registering the bridge? There are enough possible cases. I
think this also applies to other patches in the series (BTW, including
the msm/hdmi, which I ack'ed).

> 
> Signed-off-by: Luca Ceresoli <luca.ceresoli at bootlin.com>
> ---
>  drivers/gpu/drm/bridge/lontium-lt9611uxc.c | 5 ++---
>  1 file changed, 2 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/gpu/drm/bridge/lontium-lt9611uxc.c b/drivers/gpu/drm/bridge/lontium-lt9611uxc.c
> index 11aab07d88df..55b80a488c33 100644
> --- a/drivers/gpu/drm/bridge/lontium-lt9611uxc.c
> +++ b/drivers/gpu/drm/bridge/lontium-lt9611uxc.c
> @@ -35,7 +35,6 @@
>  struct lt9611uxc {
>  	struct device *dev;
>  	struct drm_bridge bridge;
> -	struct drm_bridge *next_bridge;
>  
>  	struct regmap *regmap;
>  	/* Protects all accesses to registers by stopping the on-chip MCU */
> @@ -284,7 +283,7 @@ static int lt9611uxc_bridge_attach(struct drm_bridge *bridge,
>  {
>  	struct lt9611uxc *lt9611uxc = bridge_to_lt9611uxc(bridge);
>  
> -	return drm_bridge_attach(encoder, lt9611uxc->next_bridge,
> +	return drm_bridge_attach(encoder, lt9611uxc->bridge.next_bridge,
>  				 bridge, flags);
>  }
>  
> @@ -487,7 +486,7 @@ static int lt9611uxc_parse_dt(struct device *dev,
>  
>  	lt9611uxc->dsi1_node = of_graph_get_remote_node(dev->of_node, 1, -1);
>  
> -	return drm_of_find_panel_or_bridge(dev->of_node, 2, -1, NULL, &lt9611uxc->next_bridge);
> +	return of_drm_get_bridge_by_endpoint(dev->of_node, 2, -1, &lt9611uxc->bridge.next_bridge);
>  }
>  
>  static int lt9611uxc_gpio_init(struct lt9611uxc *lt9611uxc)
> 
> -- 
> 2.53.0
> 

-- 
With best wishes
Dmitry