[PATCH v2 1/3] drm/bridge: imx8mp-hdmi-tx: switch to bridge DRM_BRIDGE_ATTACH_NO_CONNECTOR

[Ying Liu]

On 12/26/2024, Marek Vasut wrote:
> On 12/24/24 5:21 AM, Dmitry Baryshkov wrote:
> > On Tue, Dec 24, 2024 at 02:46:14AM +0100, Marek Vasut wrote:
> >> The dw-hdmi output_port is set to 1 in order to look for a connector
> >> next bridge in order to get DRM_BRIDGE_ATTACH_NO_CONNECTOR
> working.
> >> The output_port set to 1 makes the DW HDMI driver core look up the
> >> next bridge in DT, where the next bridge is often the hdmi-connector .
> >>
> >> Similar to 0af5e0b41110 ("drm/meson: encoder_hdmi: switch to bridge
> DRM_BRIDGE_ATTACH_NO_CONNECTOR")
> >>
> >> Signed-off-by: Marek Vasut <marex at denx.de>
> >> ---
> >> Cc: Andrzej Hajda <andrzej.hajda at intel.com>
> >> Cc: David Airlie <airlied at gmail.com>
> >> Cc: Fabio Estevam <festevam at gmail.com>
> >> Cc: Jernej Skrabec <jernej.skrabec at gmail.com>
> >> Cc: Jonas Karlman <jonas at kwiboo.se>
> >> Cc: Laurent Pinchart <Laurent.pinchart at ideasonboard.com>
> >> Cc: Liu Ying <victor.liu at nxp.com>
> >> Cc: Maarten Lankhorst <maarten.lankhorst at linux.intel.com>
> >> Cc: Maxime Ripard <mripard at kernel.org>
> >> Cc: Neil Armstrong <neil.armstrong at linaro.org>
> >> Cc: Pengutronix Kernel Team <kernel at pengutronix.de>
> >> Cc: Robert Foss <rfoss at kernel.org>
> >> Cc: Sascha Hauer <s.hauer at pengutronix.de>
> >> Cc: Shawn Guo <shawnguo at kernel.org>
> >> Cc: Simona Vetter <simona at ffwll.ch>
> >> Cc: Stefan Agner <stefan at agner.ch>
> >> Cc: Thomas Zimmermann <tzimmermann at suse.de>
> >> Cc: dri-devel at lists.freedesktop.org
> >> Cc: imx at lists.linux.dev
> >> Cc: linux-arm-kernel at lists.infradead.org
> >> ---
> >> V2: No change
> >> ---
> >>   drivers/gpu/drm/bridge/imx/Kconfig          | 1 +
> >>   drivers/gpu/drm/bridge/imx/imx8mp-hdmi-tx.c | 1 +
> >>   2 files changed, 2 insertions(+)
> >>
> >> diff --git a/drivers/gpu/drm/bridge/imx/Kconfig
> b/drivers/gpu/drm/bridge/imx/Kconfig
> >> index 9a480c6abb856..d8e9fbf75edbb 100644
> >> --- a/drivers/gpu/drm/bridge/imx/Kconfig
> >> +++ b/drivers/gpu/drm/bridge/imx/Kconfig
> >> @@ -27,6 +27,7 @@ config DRM_IMX8MP_DW_HDMI_BRIDGE
> >>   config DRM_IMX8MP_HDMI_PVI
> >>   	tristate "Freescale i.MX8MP HDMI PVI bridge support"
> >>   	depends on OF
> >> +	select DRM_DISPLAY_CONNECTOR
> >>   	help
> >>   	  Choose this to enable support for the internal HDMI TX Parallel
> >>   	  Video Interface found on the Freescale i.MX8MP SoC.
> >> diff --git a/drivers/gpu/drm/bridge/imx/imx8mp-hdmi-tx.c
> b/drivers/gpu/drm/bridge/imx/imx8mp-hdmi-tx.c
> >> index 1e7a789ec2890..4ebae5ad072ad 100644
> >> --- a/drivers/gpu/drm/bridge/imx/imx8mp-hdmi-tx.c
> >> +++ b/drivers/gpu/drm/bridge/imx/imx8mp-hdmi-tx.c
> >> @@ -101,6 +101,7 @@ static int imx8mp_dw_hdmi_probe(struct
> platform_device *pdev)
> >>   	plat_data->phy_name = "SAMSUNG HDMI TX PHY";
> >>   	plat_data->priv_data = hdmi;
> >>   	plat_data->phy_force_vendor = true;
> >> +	plat_data->output_port = 1;
> >
> > Quoting my feedback to a similar Liu's patch:
> >
> > This will break compatibility with older DT files, which don't have
> > output port. I think you need to add output_port_optional flag to
> > dw_hdmi_plat_data and still return 0 from dw_hdmi_parse_dt() if the flag
> > is set, but there is no remote node.
> Looking at the upstream imx8mp*dts , the oldest commit which adds HDMI
> support is commit:
> 
> 3e67a1ddd56d ("arm64: dts: imx8mp: Enable HDMI on
> TQMa8MPxL/MBa8MPxL")
> 
> That already contains the HDMI connector node. Every follow up addition
> of HDMI to another device has been a copy of the same commit, with
> connector, so I think it is safe to say, no upstream DT is going to be
> broken by this change. Do we care about hypothetical downstream DTs
> which may be missing the connector ?

These have no HDMI connector nodes:
arch/arm64/boot/dts/freescale/imx8mp-aristainetos3a-som-v1.dtsi
arch/arm64/boot/dts/freescale/imx8mp-kontron-bl-osm-s.dts
arch/arm64/boot/dts/freescale/imx8mp-kontron-smarc-eval-carrier.dts
arch/arm64/boot/dts/freescale/imx8mp-msc-sm2s-ep1.dts

Regards,
Liu Ying