On Fri, 30 Jan 2026 20:31:11 +0100
"Luca Ceresoli" <[email protected]> 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
