[PATCH 5.15 396/913] drm/edid: Split deep color modes between RGB and YUV444

From: Greg Kroah-Hartman
Date: Tue Apr 05 2022 - 20:41:39 EST


From: Maxime Ripard <maxime@xxxxxxxxxx>

[ Upstream commit 4adc33f36d80489339f1b43dfeee96bb9ea8e459 ]

The current code assumes that the RGB444 and YUV444 formats are the
same, but the HDMI 2.0 specification states that:

The three DC_XXbit bits above only indicate support for RGB 4:4:4 at
that pixel size. Support for YCBCR 4:4:4 in Deep Color modes is
indicated with the DC_Y444 bit. If DC_Y444 is set, then YCBCR 4:4:4
is supported for all modes indicated by the DC_XXbit flags.

So if we have YUV444 support and any DC_XXbit flag set but the DC_Y444
flag isn't, we'll assume that we support that deep colour mode for
YUV444 which breaks the specification.

In order to fix this, let's split the edid_hdmi_dc_modes field in struct
drm_display_info into two fields, one for RGB444 and one for YUV444.

Suggested-by: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx>
Fixes: d0c94692e0a3 ("drm/edid: Parse and handle HDMI deep color modes.")
Signed-off-by: Maxime Ripard <maxime@xxxxxxxxxx>
Reviewed-by: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx>
Link: https://patchwork.freedesktop.org/patch/msgid/20220120151625.594595-4-maxime@xxxxxxxxxx
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
drivers/gpu/drm/amd/amdgpu/amdgpu_connectors.c | 2 +-
drivers/gpu/drm/drm_edid.c | 7 ++++---
drivers/gpu/drm/i915/display/intel_hdmi.c | 4 ++--
drivers/gpu/drm/radeon/radeon_connectors.c | 2 +-
include/drm/drm_connector.h | 12 +++++++++---
5 files changed, 17 insertions(+), 10 deletions(-)

--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_connectors.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_connectors.c
@@ -175,7 +175,7 @@ int amdgpu_connector_get_monitor_bpc(str

/* Check if bpc is within clock limit. Try to degrade gracefully otherwise */
if ((bpc == 12) && (mode_clock * 3/2 > max_tmds_clock)) {
- if ((connector->display_info.edid_hdmi_dc_modes & DRM_EDID_HDMI_DC_30) &&
+ if ((connector->display_info.edid_hdmi_rgb444_dc_modes & DRM_EDID_HDMI_DC_30) &&
(mode_clock * 5/4 <= max_tmds_clock))
bpc = 10;
else
--- a/drivers/gpu/drm/drm_edid.c
+++ b/drivers/gpu/drm/drm_edid.c
@@ -5004,21 +5004,21 @@ static void drm_parse_hdmi_deep_color_in

if (hdmi[6] & DRM_EDID_HDMI_DC_30) {
dc_bpc = 10;
- info->edid_hdmi_dc_modes |= DRM_EDID_HDMI_DC_30;
+ info->edid_hdmi_rgb444_dc_modes |= DRM_EDID_HDMI_DC_30;
DRM_DEBUG("%s: HDMI sink does deep color 30.\n",
connector->name);
}

if (hdmi[6] & DRM_EDID_HDMI_DC_36) {
dc_bpc = 12;
- info->edid_hdmi_dc_modes |= DRM_EDID_HDMI_DC_36;
+ info->edid_hdmi_rgb444_dc_modes |= DRM_EDID_HDMI_DC_36;
DRM_DEBUG("%s: HDMI sink does deep color 36.\n",
connector->name);
}

if (hdmi[6] & DRM_EDID_HDMI_DC_48) {
dc_bpc = 16;
- info->edid_hdmi_dc_modes |= DRM_EDID_HDMI_DC_48;
+ info->edid_hdmi_rgb444_dc_modes |= DRM_EDID_HDMI_DC_48;
DRM_DEBUG("%s: HDMI sink does deep color 48.\n",
connector->name);
}
@@ -5035,6 +5035,7 @@ static void drm_parse_hdmi_deep_color_in

/* YCRCB444 is optional according to spec. */
if (hdmi[6] & DRM_EDID_HDMI_DC_Y444) {
+ info->edid_hdmi_ycbcr444_dc_modes = info->edid_hdmi_rgb444_dc_modes;
DRM_DEBUG("%s: HDMI sink does YCRCB444 in deep color.\n",
connector->name);
}
--- a/drivers/gpu/drm/i915/display/intel_hdmi.c
+++ b/drivers/gpu/drm/i915/display/intel_hdmi.c
@@ -1892,7 +1892,7 @@ static bool intel_hdmi_bpc_possible(stru
if (ycbcr420_output)
return hdmi->y420_dc_modes & DRM_EDID_YCBCR420_DC_36;
else
- return info->edid_hdmi_dc_modes & DRM_EDID_HDMI_DC_36;
+ return info->edid_hdmi_rgb444_dc_modes & DRM_EDID_HDMI_DC_36;
case 10:
if (DISPLAY_VER(i915) < 11)
return false;
@@ -1903,7 +1903,7 @@ static bool intel_hdmi_bpc_possible(stru
if (ycbcr420_output)
return hdmi->y420_dc_modes & DRM_EDID_YCBCR420_DC_30;
else
- return info->edid_hdmi_dc_modes & DRM_EDID_HDMI_DC_30;
+ return info->edid_hdmi_rgb444_dc_modes & DRM_EDID_HDMI_DC_30;
case 8:
return true;
default:
--- a/drivers/gpu/drm/radeon/radeon_connectors.c
+++ b/drivers/gpu/drm/radeon/radeon_connectors.c
@@ -204,7 +204,7 @@ int radeon_get_monitor_bpc(struct drm_co

/* Check if bpc is within clock limit. Try to degrade gracefully otherwise */
if ((bpc == 12) && (mode_clock * 3/2 > max_tmds_clock)) {
- if ((connector->display_info.edid_hdmi_dc_modes & DRM_EDID_HDMI_DC_30) &&
+ if ((connector->display_info.edid_hdmi_rgb444_dc_modes & DRM_EDID_HDMI_DC_30) &&
(mode_clock * 5/4 <= max_tmds_clock))
bpc = 10;
else
--- a/include/drm/drm_connector.h
+++ b/include/drm/drm_connector.h
@@ -566,10 +566,16 @@ struct drm_display_info {
bool rgb_quant_range_selectable;

/**
- * @edid_hdmi_dc_modes: Mask of supported hdmi deep color modes. Even
- * more stuff redundant with @bus_formats.
+ * @edid_hdmi_dc_rgb444_modes: Mask of supported hdmi deep color modes
+ * in RGB 4:4:4. Even more stuff redundant with @bus_formats.
*/
- u8 edid_hdmi_dc_modes;
+ u8 edid_hdmi_rgb444_dc_modes;
+
+ /**
+ * @edid_hdmi_dc_ycbcr444_modes: Mask of supported hdmi deep color
+ * modes in YCbCr 4:4:4. Even more stuff redundant with @bus_formats.
+ */
+ u8 edid_hdmi_ycbcr444_dc_modes;

/**
* @cea_rev: CEA revision of the HDMI sink.