Re: [PATCH v2] drm/rockchip: dw_hdmi_qp: attach the HDMI Colorspace connector property

["Diederik de Haas" <diederik@cknow-tech.com>]

On Wed Aug 5, 2026 at 5:33 PM CEST, Igor Paunovic wrote:
> The RK3588 HDMI QP output never exposes the "Colorspace" connector
> property, so userspace has no way to request BT.2020 colorimetry.
>
> Everything needed to signal it is already in place. The connector comes
> from drm_bridge_connector_init(), which calls drmm_connector_hdmi_init()
> and attaches "max bpc", "HDR_OUTPUT_METADATA" and the output color
> format, and the HDMI state helper feeds conn_state->colorspace into the
> AVI infoframe colorimetry bits via hdmi_generate_avi_infoframe() and
> drm_hdmi_avi_infoframe_colorimetry(). dw-hdmi-qp then emits the
> infoframe through its hdmi_write_avi_infoframe hook. Only the property
> itself is missing, so conn_state->colorspace stays at its default and
> the AVI infoframe always reports "no colorimetry data".
>
> The user-visible effect is that HDR is unavailable on every RK3588 HDMI
> output. KWin (Plasma 6.x) requires "Colorspace" alongside
> "HDR_OUTPUT_METADATA" and "max bpc" before it treats an output as
> wide-gamut capable, so it never offers the HDR toggle.
>
> Create and attach the property right after the bridge connector is
> initialised, as vc4_hdmi already does. Passing 0 to
> drm_mode_create_hdmi_colorspace_property() selects the full HDMI
> colorspace set defined by the core.
>
> Tested on an Orange Pi 5 Plus driving a Samsung Odyssey G70B: KWin now
> offers the HDR toggle, the connector property switches to BT2020_RGB
> once HDR is enabled, and the output runs 4K@144 at 10 bpc.
>
> Signed-off-by: Igor Paunovic <royalnet026@gmail.com>
> ---
> Changes in v2:
> - Regenerated with git format-patch. v1 was a hand-assembled diff: it
>   carried no "diff --git" header, no diffstat, and no function context on
>   the @@ hunk header. That is the most likely reason it never showed up in
>   patchwork and got no review in three weeks.
> - Rebased onto drm-misc-next (97c03b32b28a), the right tree for this
>   change. The hunk is unchanged apart from its new offset and the function
>   context that format-patch adds.
> - Reworded the commit message to lead with the user-visible effect and to
>   name the exact core path that consumes conn_state->colorspace.
> - Trimmed the in-code comment to a single line; the reasoning now lives in
>   the commit message instead. No functional change from v1: the two API
>   calls and their placement are the same.
> - An automated review of v1 flagged that returning an error from
>   dw_hdmi_qp_rockchip_bind() leaves hdmi->hpd_work queued. That gap
>   pre-dates this patch and is shared by every existing error path in
>   bind() (drmm_encoder_init(), dw_hdmi_qp_bind(),
>   drm_bridge_connector_init()), since cancel_delayed_work_sync() runs only
>   in dw_hdmi_qp_rockchip_unbind(), which the component framework does not
>   call for a failed bind(). It is already being addressed in the HDMI 2.0
>   series below ("Cancel pending HPD work on suspend", 30/69, and "Control
>   the HPD IRQ line via the bridge HPD ops", 37/69), so this patch adds
>   nothing for it.
>
> v1: https://lore.kernel.org/all/20260714202850.40999-1-royalnet026@gmail.com/
> HDMI 2.0 series: https://lore.kernel.org/all/20260731-dw-hdmi-qp-scramb-v10-0-294364b2cf15@collabora.com/

Explicitly adding the author of that patch set into the loop.

Cheers,
  Diederik

>  drivers/gpu/drm/rockchip/dw_hdmi_qp-rockchip.c | 7 +++++++
>  1 file changed, 7 insertions(+)
>
> diff --git a/drivers/gpu/drm/rockchip/dw_hdmi_qp-rockchip.c b/drivers/gpu/drm/rockchip/dw_hdmi_qp-rockchip.c
> index 9c4cf68d79d5..35d04680d011 100644
> --- a/drivers/gpu/drm/rockchip/dw_hdmi_qp-rockchip.c
> +++ b/drivers/gpu/drm/rockchip/dw_hdmi_qp-rockchip.c
> @@ -695,6 +695,13 @@ static int dw_hdmi_qp_rockchip_bind(struct device *dev, struct device *master,
>  		return dev_err_probe(hdmi->dev, PTR_ERR(connector),
>  				     "Failed to init bridge connector\n");
>  
> +	/* Passing 0 selects the full HDMI colorspace set defined by the core. */
> +	ret = drm_mode_create_hdmi_colorspace_property(connector, 0);
> +	if (ret)
> +		return ret;
> +
> +	drm_connector_attach_colorspace_property(connector);
> +
>  	return 0;
>  }
>  
>
> base-commit: 97c03b32b28a9f7f13f768f2b06e1eaafe850e66