On Wed, Jan 21, 2026 at 03:45:12PM +0100, Nicolas Frattaroli wrote:
> With the introduction of the "color format" DRM property, which allows
> userspace to request a specific color format, the HDMI state helper
> should implement this.
> 
> Implement it by checking whether the property is set and set to
> something other than auto. If so, pass the requested color format, and
> otherwise set RGB.
> 
> Signed-off-by: Nicolas Frattaroli <[email protected]>
> ---
>  drivers/gpu/drm/display/drm_hdmi_state_helper.c | 12 +++++++++++-
>  1 file changed, 11 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/gpu/drm/display/drm_hdmi_state_helper.c 
> b/drivers/gpu/drm/display/drm_hdmi_state_helper.c
> index a1d16762ac7a..1ea3b9c93aa5 100644
> --- a/drivers/gpu/drm/display/drm_hdmi_state_helper.c
> +++ b/drivers/gpu/drm/display/drm_hdmi_state_helper.c
> @@ -649,11 +649,21 @@ hdmi_compute_config(const struct drm_connector 
> *connector,
>       unsigned int max_bpc = clamp_t(unsigned int,
>                                      conn_state->max_bpc,
>                                      8, connector->max_bpc);
> +     enum hdmi_colorspace hdmi_colorspace =
> +             drm_color_format_to_hdmi_colorspace(conn_state->color_format);
>       int ret;
>  
>       ret = hdmi_compute_format_bpc(connector, conn_state, mode, max_bpc,
> -                                   HDMI_COLORSPACE_RGB);
> +                                   hdmi_colorspace);

I still think we shoud be more explicit there, with something like

if (conn_state->color_format != DRM_COLOR_FORMAT_AUTO) {
        return hdmi_compute_format_bpc(connector, conn_state, mode, max_bpc, 
drm_color_format_to_hdmi_colorspace(conn_state->color_format))
}

ret = hdmi_compute_format_bpc(connector, conn_state, mode, max_bpc,
                              HDMI_COLORSPACE_RGB);

Otherwise, it's pretty easy to get confused between the behaviour
drm_color_format_to_hdmi_colorspace() to return RGB when it get AUTO...

>       if (ret) {
> +             /* If a color format was explicitly requested, don't fall back 
> */
> +             if (conn_state->color_format) {

... or that auto is actually 0 in that enum.

Or between the auto and non-auto code path.

Maxime

Attachment: signature.asc
Description: PGP signature

Reply via email to