[PATCH v5 20/25] drm/tilcdc: Use devm_drm_of_get_bridge() helper

[Kory Maincent]

On Fri, 30 Jan 2026 20:31:11 +0100
"Luca Ceresoli" <luca.ceresoli at bootlin.com> wrote:

> Hi Kory,
> 
> On Fri Jan 23, 2026 at 5:12 PM CET, Kory Maincent (TI.com) wrote:
> > Replace drm_of_find_panel_or_bridge() with the newer
> > devm_drm_of_get_bridge() helper which simplifies the code by:
> > - Automatically handling both panel and bridge cases internally
> > - Managing the panel-to-bridge conversion when needed
> > - Using devres for resource management, eliminating manual cleanup
> >
> > This removes the need for explicit panel-to-bridge conversion via
> > devm_drm_panel_bridge_add_typed() and the associated error handling path.

...

> >  	encoder = drmm_simple_encoder_alloc(ddev, struct tilcdc_encoder,
> >  					    base, DRM_MODE_ENCODER_NONE);
> > @@ -73,12 +70,5 @@ int tilcdc_encoder_create(struct drm_device *ddev)
> >  	}
> >  	priv->encoder = encoder;
> >
> > -	if (panel) {
> > -		bridge = devm_drm_panel_bridge_add_typed(ddev->dev, panel,
> > -
> > DRM_MODE_CONNECTOR_DPI);  
> 
> You are introducing a subtle difference here: while you pass the connector
> type to devm_drm_panel_bridge_add_typed(), devm_drm_of_get_bridge() does
> not take it and expects it to ahve been set previously and errors out if it
> hasn't.
> 
> Can you ensure the connector type is alway set before this
> devm_drm_of_get_bridge() call?

The connector type should be set by the bridge or the panel driver.

https://elixir.bootlin.com/linux/v6.18.6/source/drivers/gpu/drm/bridge/panel.c#L397
 * This function is deprecated and should not be used in new drivers. Use
 * devm_drm_panel_bridge_add() instead, and fix panel drivers as necessary if
 * they don't report a connector type.

Regards,
-- 
Köry Maincent, Bootlin
Embedded Linux and kernel engineering
https://bootlin.com