Re: [PATCH 5/8] drm/bridge: dw-hdmi: warn on unsupported attach combination

Liu Ying
2026-03-26T07:34:09Z

On Fri, Mar 20, 2026 at 11:46:16AM +0100, Luca Ceresoli wrote:
> dw-hdmi can operate in two different modes, depending on the platform data
> as set by the driver:
>
> A. hdmi->plat_data->output_port = 0:
> the HDMI output (port@1) in device tree is not used
>
> B. hdmi->plat_data->output_port = 1:
> the HDMI output (port@1) is parsed to find the next bridge
>
> Only case B is supported when the DRM_BRIDGE_ATTACH_NO_CONNECTOR flag is
> passed to the attach callback. Emit a warning when this is violated. Also
> return -EINVAL which would be returned by drm_bridge_attach() right after
> anyway.
>
> Signed-off-by: Luca Ceresoli <luca.ceresoli@bootlin.com>
>
> ---
>
> Note: Returning when teh warning triggers does not change the functional
> behaviour of this function. It is not strictly necessary in this patch but
> it will have to be done anyway in the following patch.
> ---
> drivers/gpu/drm/bridge/synopsys/dw-hdmi.c | 4 ++++
> 1 file changed, 4 insertions(+)

Reviewed-by: Liu Ying <victor.liu@nxp.com>

--
Regards,
Liu Ying