From: Maxime Ripard maxime@cerno.tech
commit ecbd4912a693b862e25cba0a6990a8c95b00721e upstream.
In order to fill the drm_display_info structure each time an EDID is read, the code currently will call drm_add_display_info with the parsed EDID.
drm_add_display_info will then call drm_reset_display_info to reset all the fields to 0, and then set them to the proper value depending on the EDID.
In the color_formats case, we will thus report that we don't support any color format, and then fill it back with RGB444 plus the additional formats described in the EDID Feature Support byte.
However, since that byte only contains format-related bits since the 1.4 specification, this doesn't happen if the EDID is following an earlier specification. In turn, it means that for one of these EDID, we end up with color_formats set to 0.
The EDID 1.3 specification never really specifies what it means by RGB exactly, but since both HDMI and DVI will use RGB444, it's fairly safe to assume it's supposed to be RGB444.
Let's move the addition of RGB444 to color_formats earlier in drm_add_display_info() so that it's always set for a digital display.
Fixes: da05a5a71ad8 ("drm: parse color format support for digital displays") Cc: Ville Syrjälä ville.syrjala@linux.intel.com Reported-by: Matthias Reichl hias@horus.com Signed-off-by: Maxime Ripard maxime@cerno.tech Reviewed-by: Ville Syrjälä ville.syrjala@linux.intel.com Link: https://patchwork.freedesktop.org/patch/msgid/20220203115416.1137308-1-maxim... Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/gpu/drm/drm_edid.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
--- a/drivers/gpu/drm/drm_edid.c +++ b/drivers/gpu/drm/drm_edid.c @@ -4418,6 +4418,7 @@ static void drm_add_display_info(struct if (!(edid->input & DRM_EDID_INPUT_DIGITAL)) return;
+ info->color_formats |= DRM_COLOR_FORMAT_RGB444; drm_parse_cea_ext(connector, edid);
/* @@ -4466,7 +4467,6 @@ static void drm_add_display_info(struct DRM_DEBUG("%s: Assigning EDID-1.4 digital sink color depth as %d bpc.\n", connector->name, info->bpc);
- info->color_formats |= DRM_COLOR_FORMAT_RGB444; if (edid->features & DRM_EDID_FEATURE_RGB_YCRCB444) info->color_formats |= DRM_COLOR_FORMAT_YCRCB444; if (edid->features & DRM_EDID_FEATURE_RGB_YCRCB422)