[PATCH v5 03/11] drm/msm/hdmi: switch to of_drm_get_bridge_by_endpoint()

[Dmitry Baryshkov]

On Thu, May 07, 2026 at 03:45:21PM +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.
> 
> Signed-off-by: Luca Ceresoli <luca.ceresoli at bootlin.com>
> 
> ---
> 
> Changes in v5:
> - simplify error management code flow
> 
> Changes in v4:
> - ensure next_bridge is put on later probe failures
> 
> Changes in v3:
> - fix ERR_PTR deref when -ENODEV is returned
> ---
>  drivers/gpu/drm/msm/hdmi/hdmi.c | 14 +++++++++++---
>  1 file changed, 11 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/gpu/drm/msm/hdmi/hdmi.c b/drivers/gpu/drm/msm/hdmi/hdmi.c
> index d9491aac1a89..3640be8c1bf9 100644
> --- a/drivers/gpu/drm/msm/hdmi/hdmi.c
> +++ b/drivers/gpu/drm/msm/hdmi/hdmi.c
> @@ -285,9 +285,14 @@ static int msm_hdmi_dev_probe(struct platform_device *pdev)
>  	spin_lock_init(&hdmi->reg_lock);
>  	mutex_init(&hdmi->state_mutex);
>  
> -	ret = drm_of_find_panel_or_bridge(dev_of_node(dev), 1, 0, NULL, &hdmi->next_bridge);
> -	if (ret && ret != -ENODEV)
> -		return ret;
> +	struct drm_bridge *next_bridge __free(drm_bridge_put) =
> +		of_drm_get_bridge_by_endpoint(dev_of_node(dev), 1, 0);
> +	if (IS_ERR(next_bridge)) {
> +		if (PTR_ERR(next_bridge) != -ENODEV)
> +			return PTR_ERR(next_bridge);
> +
> +		next_bridge = NULL;
> +	}
>  
>  	hdmi->mmio = msm_ioremap(pdev, "core_physical");
>  	if (IS_ERR(hdmi->mmio))
> @@ -367,6 +372,8 @@ static int msm_hdmi_dev_probe(struct platform_device *pdev)
>  	if (ret)
>  		goto err_put_phy;
>  
> +	hdmi->next_bridge = no_free_ptr(next_bridge);

Following the question on IRC. Yes, this seems to be too late. So, I'd
suggest keeping the current assignment place (and call drm_bridge_put()
accordingly). I'll rework that to use bridge.next_bridge afterwards.

> +
>  	return 0;
>  
>  err_put_phy:
> @@ -381,6 +388,7 @@ static void msm_hdmi_dev_remove(struct platform_device *pdev)
>  	component_del(&pdev->dev, &msm_hdmi_ops);
>  
>  	msm_hdmi_put_phy(hdmi);
> +	drm_bridge_put(hdmi->next_bridge);
>  }
>  
>  static int msm_hdmi_runtime_suspend(struct device *dev)
> 
> -- 
> 2.53.0
> 

-- 
With best wishes
Dmitry