Re: [PATCH v4 08/11] drm/bridge: adv7511: switch to of_drm_get_bridge_by_endpoint()

[Laurent Pinchart <laurent.pinchart@ideasonboard.com>]

Hi Luca,

Thank you for the patch.

On Mon, May 04, 2026 at 12:45:11PM +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.
> 
> Tested-by: Biju Das <biju.das.jz@bp.renesas.com>
> Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>
> Signed-off-by: Luca Ceresoli <luca.ceresoli@bootlin.com>

Reviewed-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>

> ---
> Changes in v3:
> - fix ERR_PTR deref when -ENODEV is returned
> ---
>  drivers/gpu/drm/bridge/adv7511/adv7511.h     |  1 -
>  drivers/gpu/drm/bridge/adv7511/adv7511_drv.c | 15 +++++++++------
>  2 files changed, 9 insertions(+), 7 deletions(-)
> 
> diff --git a/drivers/gpu/drm/bridge/adv7511/adv7511.h b/drivers/gpu/drm/bridge/adv7511/adv7511.h
> index 8be7266fd4f4..12c95198d9a4 100644
> --- a/drivers/gpu/drm/bridge/adv7511/adv7511.h
> +++ b/drivers/gpu/drm/bridge/adv7511/adv7511.h
> @@ -354,7 +354,6 @@ struct adv7511 {
>  	enum drm_connector_status status;
>  	bool powered;
>  
> -	struct drm_bridge *next_bridge;
>  	struct drm_display_mode curr_mode;
>  
>  	unsigned int f_tmds;
> diff --git a/drivers/gpu/drm/bridge/adv7511/adv7511_drv.c b/drivers/gpu/drm/bridge/adv7511/adv7511_drv.c
> index f318080f1139..8304978535e4 100644
> --- a/drivers/gpu/drm/bridge/adv7511/adv7511_drv.c
> +++ b/drivers/gpu/drm/bridge/adv7511/adv7511_drv.c
> @@ -849,8 +849,8 @@ static int adv7511_bridge_attach(struct drm_bridge *bridge,
>  	struct adv7511 *adv = bridge_to_adv7511(bridge);
>  	int ret = 0;
>  
> -	if (adv->next_bridge) {
> -		ret = drm_bridge_attach(encoder, adv->next_bridge, bridge,
> +	if (adv->bridge.next_bridge) {
> +		ret = drm_bridge_attach(encoder, adv->bridge.next_bridge, bridge,
>  					flags | DRM_BRIDGE_ATTACH_NO_CONNECTOR);
>  		if (ret)
>  			return ret;
> @@ -1249,10 +1249,13 @@ static int adv7511_probe(struct i2c_client *i2c)
>  
>  	memset(&link_config, 0, sizeof(link_config));
>  
> -	ret = drm_of_find_panel_or_bridge(dev->of_node, 1, -1, NULL,
> -					  &adv7511->next_bridge);
> -	if (ret && ret != -ENODEV)
> -		return ret;
> +	adv7511->bridge.next_bridge = of_drm_get_bridge_by_endpoint(dev->of_node, 1, -1);
> +	if (IS_ERR(adv7511->bridge.next_bridge)) {
> +		if (PTR_ERR(adv7511->bridge.next_bridge) == -ENODEV)
> +			adv7511->bridge.next_bridge = NULL;
> +		else
> +			return PTR_ERR(adv7511->bridge.next_bridge);
> +	}
>  
>  	if (adv7511->info->link_config)
>  		ret = adv7511_parse_dt(dev->of_node, &link_config);

-- 
Regards,

Laurent Pinchart