Hi Marek,
Thank you for the patch.
On Sun, Jan 05, 2025 at 08:06:03PM +0100, Marek Vasut wrote:
> Add a flag meant purely to work around broken i.MX8MP DTs which enable
> HDMI but do not contain the HDMI connector node. This flag allows such
> DTs to work by creating the connector in the HDMI bridge driver. Do not
> use this flag, do not proliferate this flag, please fix your DTs and add
> the connector node this way:
>
> ```
> / {
> hdmi-connector {
> compatible = "hdmi-connector";
> label = "FIXME-Board-Specific-Connector-Label"; // Modify this
> type = "a";
>
> port {
> hdmi_connector_in: endpoint {
> remote-endpoint = <&hdmi_tx_out>;
> };
> };
> };
> };
>
> &hdmi_tx {
> ...
>
> ports {
> port@1 {
> hdmi_tx_out: endpoint {
> remote-endpoint = <&hdmi_connector_in>;
> };
> };
> };
> };
> ```
Are there any in-tree DT sources that use the old bindings ?
> Signed-off-by: Marek Vasut <marex@xxxxxxx>
> ---
> Cc: Andrzej Hajda <andrzej.hajda@xxxxxxxxx>
> Cc: David Airlie <airlied@xxxxxxxxx>
> Cc: Fabio Estevam <festevam@xxxxxxxxx>
> Cc: Jernej Skrabec <jernej.skrabec@xxxxxxxxx>
> Cc: Jonas Karlman <jonas@xxxxxxxxx>
> Cc: Laurent Pinchart <Laurent.pinchart@xxxxxxxxxxxxxxxx>
> Cc: Liu Ying <victor.liu@xxxxxxx>
> Cc: Maarten Lankhorst <maarten.lankhorst@xxxxxxxxxxxxxxx>
> Cc: Maxime Ripard <mripard@xxxxxxxxxx>
> Cc: Neil Armstrong <neil.armstrong@xxxxxxxxxx>
> Cc: Pengutronix Kernel Team <kernel@xxxxxxxxxxxxxx>
> Cc: Robert Foss <rfoss@xxxxxxxxxx>
> Cc: Sascha Hauer <s.hauer@xxxxxxxxxxxxxx>
> Cc: Shawn Guo <shawnguo@xxxxxxxxxx>
> Cc: Simona Vetter <simona@xxxxxxxx>
> Cc: Stefan Agner <stefan@xxxxxxxx>
> Cc: Thomas Zimmermann <tzimmermann@xxxxxxx>
> Cc: dri-devel@xxxxxxxxxxxxxxxxxxxxx
> Cc: imx@xxxxxxxxxxxxxxx
> Cc: linux-arm-kernel@xxxxxxxxxxxxxxxxxxx
> ---
> V3: New patch
> V4: - Add HDMI connector node addition example into commit message
> - Bail from dw_hdmi_bridge_attach() if DRM_BRIDGE_ATTACH_NO_CONNECTOR
> is set and there is no hdmi->next_bridge , so the connector can
> be created in scanout driver.
> ---
> drivers/gpu/drm/bridge/synopsys/dw-hdmi.c | 8 ++++++--
> include/drm/bridge/dw_hdmi.h | 2 ++
> 2 files changed, 8 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c b/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c
> index 996733ed2c004..e84693faf46dc 100644
> --- a/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c
> +++ b/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c
> @@ -2893,9 +2893,13 @@ static int dw_hdmi_bridge_attach(struct drm_bridge *bridge,
> {
> struct dw_hdmi *hdmi = bridge->driver_private;
>
> - if (flags & DRM_BRIDGE_ATTACH_NO_CONNECTOR)
> + if (flags & DRM_BRIDGE_ATTACH_NO_CONNECTOR) {
> + if (!hdmi->next_bridge)
> + return 0;
> +
> return drm_bridge_attach(bridge->encoder, hdmi->next_bridge,
> bridge, flags);
> + }
>
> return dw_hdmi_connector_create(hdmi);
> }
> @@ -3298,7 +3302,7 @@ static int dw_hdmi_parse_dt(struct dw_hdmi *hdmi)
> hdmi->plat_data->output_port,
> -1);
> if (!remote)
> - return -ENODEV;
> + return hdmi->plat_data->output_port_optional ? 0 : -ENODEV;
Let's complain loudly with a WARN_ON if output_port_optional is set.
>
> hdmi->next_bridge = of_drm_find_bridge(remote);
> of_node_put(remote);
> diff --git a/include/drm/bridge/dw_hdmi.h b/include/drm/bridge/dw_hdmi.h
> index 6a46baa0737cd..3bb6e633424a8 100644
> --- a/include/drm/bridge/dw_hdmi.h
> +++ b/include/drm/bridge/dw_hdmi.h
> @@ -127,6 +127,8 @@ struct dw_hdmi_plat_data {
> struct regmap *regm;
>
> unsigned int output_port;
> + /* Used purely by MX8MP HDMI to work around broken DTs without HDMI connector node. */
> + bool output_port_optional;
>
> unsigned long input_bus_encoding;
> bool use_drm_infoframe;
--
Regards,
Laurent Pinchart
