Hi Hsin-Yi, thanks for this nice series.
On Mon, Jun 06, 2022 at 11:24:23PM +0800, Hsin-Yi Wang wrote:
Panels usually call drm_connector_set_panel_orientation(), which is later than drm/kms driver calling drm_dev_register(). This leads to a WARN()[1].
The orientation property is known earlier. For example, some panels parse the property through device tree during probe.
The series add a panel API drm_panel_get_orientation() for drm/kms drivers. The drivers can use the API to get panel's orientation, so they can call drm_connector_set_panel_orientation() before drm_dev_register().
Panel needs to implement .get_orientation callback to return the property.
The following comment appears in every panel driver: + /* + * drm drivers are expected to call drm_panel_get_orientation() to get + * panel's orientation then drm_connector_set_panel_orientation() to + * set the property before drm_dev_register(). Otherwise there will be + * a WARN_ON if orientation is set after drm is registered. + */
Please move it to the drm_panel c or h file, it is noise to add it to all panel drivers.
Sam