On Tue, Dec 31, 2024 at 08:28:48PM +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.
>
> Signed-off-by: Marek Vasut <ma...@denx.de>
Please describe that it is required for backwards compatibility with the
existing DTs. I think it is a good idea unless Shawn, Sascha or Fabio
tell that we should ignore backwards compatibility.
With that in mind:
Reviewed-by: Dmitry Baryshkov <dmitry.barysh...@linaro.org>
> ---
> Cc: Andrzej Hajda <andrzej.ha...@intel.com>
> Cc: David Airlie <airl...@gmail.com>
> Cc: Fabio Estevam <feste...@gmail.com>
> Cc: Jernej Skrabec <jernej.skra...@gmail.com>
> Cc: Jonas Karlman <jo...@kwiboo.se>
> Cc: Laurent Pinchart <laurent.pinch...@ideasonboard.com>
> Cc: Liu Ying <victor....@nxp.com>
> Cc: Maarten Lankhorst <maarten.lankho...@linux.intel.com>
> Cc: Maxime Ripard <mrip...@kernel.org>
> Cc: Neil Armstrong <neil.armstr...@linaro.org>
> Cc: Pengutronix Kernel Team <ker...@pengutronix.de>
> Cc: Robert Foss <rf...@kernel.org>
> Cc: Sascha Hauer <s.ha...@pengutronix.de>
> Cc: Shawn Guo <shawn...@kernel.org>
> Cc: Simona Vetter <sim...@ffwll.ch>
> Cc: Stefan Agner <ste...@agner.ch>
> Cc: Thomas Zimmermann <tzimmerm...@suse.de>
> Cc: dri-devel@lists.freedesktop.org
> Cc: i...@lists.linux.dev
> Cc: linux-arm-ker...@lists.infradead.org
> ---
> V3: New patch
> ---
> drivers/gpu/drm/bridge/synopsys/dw-hdmi.c | 12 ++++++++----
> include/drm/bridge/dw_hdmi.h | 2 ++
> 2 files changed, 10 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c
> b/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c
> index 996733ed2c004..852e73c0f686f 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)
> - return drm_bridge_attach(bridge->encoder, hdmi->next_bridge,
> - bridge, flags);
> + if (flags & DRM_BRIDGE_ATTACH_NO_CONNECTOR) {
> + if (hdmi->plat_data->output_port_optional && !hdmi->next_bridge)
> + return dw_hdmi_connector_create(hdmi);
> + else
> + 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;
>
> 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;
> --
> 2.45.2
>
--
With best wishes
Dmitry
