From: Maxime Ripard maxime@cerno.tech
[ Upstream commit 75478b3b393bcbdca4e6da76fe3a9f1a4133ec5d ]
The current code, when parsing the EDID Deep Color depths, that the YUV422 cannot be used, referring to the HDMI 1.3 Specification.
This specification, in its section 6.2.4, indeed states:
For each supported Deep Color mode, RGB 4:4:4 shall be supported and optionally YCBCR 4:4:4 may be supported.
YCBCR 4:2:2 is not permitted for any Deep Color mode.
This indeed can be interpreted like the code does, but the HDMI 1.4 specification further clarifies that statement in its section 6.2.4:
For each supported Deep Color mode, RGB 4:4:4 shall be supported and optionally YCBCR 4:4:4 may be supported.
YCBCR 4:2:2 is also 36-bit mode but does not require the further use of the Deep Color modes described in section 6.5.2 and 6.5.3.
This means that, even though YUV422 can be used with 12 bit per color, it shouldn't be treated as a deep color mode.
This is also broken with YUV444 if it's supported by the display, but DRM_EDID_HDMI_DC_Y444 isn't set. In such a case, the code will clear color_formats of the YUV444 support set previously in drm_parse_cea_ext(), but will not set it back.
Since the formats supported are already setup properly in drm_parse_cea_ext(), let's just remove the code modifying the formats in drm_parse_hdmi_deep_color_info()
Fixes: d0c94692e0a3 ("drm/edid: Parse and handle HDMI deep color modes.") Signed-off-by: Maxime Ripard maxime@cerno.tech Reviewed-by: Ville Syrjälä ville.syrjala@linux.intel.com Link: https://patchwork.freedesktop.org/patch/msgid/20220120151625.594595-3-maxime... Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/gpu/drm/drm_edid.c | 8 -------- 1 file changed, 8 deletions(-)
--- a/drivers/gpu/drm/drm_edid.c +++ b/drivers/gpu/drm/drm_edid.c @@ -4534,16 +4534,8 @@ static void drm_parse_hdmi_deep_color_in connector->name, dc_bpc); info->bpc = dc_bpc;
- /* - * Deep color support mandates RGB444 support for all video - * modes and forbids YCRCB422 support for all video modes per - * HDMI 1.3 spec. - */ - info->color_formats = DRM_COLOR_FORMAT_RGB444; - /* YCRCB444 is optional according to spec. */ if (hdmi[6] & DRM_EDID_HDMI_DC_Y444) { - info->color_formats |= DRM_COLOR_FORMAT_YCRCB444; DRM_DEBUG("%s: HDMI sink does YCRCB444 in deep color.\n", connector->name); }