[PATCH v8 07/20] drm/i915: Implement the "color format" DRM property
From: Nicolas Frattaroli
Date: Mon Feb 16 2026 - 08:04:57 EST
This includes RGB, YUV420, YUV444 and Auto. Auto will pick RGB, unless
the mode being asked for is YUV420-only, in which case it picks YUV420.
Should the explicitly requested color format not be supported by the
sink, then an error is returned to userspace, so that it can make a
better choice.
Co-developed-by: Werner Sembach <wse@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Werner Sembach <wse@xxxxxxxxxxxxxxxxxxx>
Co-developed-by: Andri Yngvason <andri@xxxxxxxxxxx>
Signed-off-by: Andri Yngvason <andri@xxxxxxxxxxx>
Co-developed-by: Marius Vlad <marius.vlad@xxxxxxxxxxxxx>
Signed-off-by: Marius Vlad <marius.vlad@xxxxxxxxxxxxx>
Signed-off-by: Nicolas Frattaroli <nicolas.frattaroli@xxxxxxxxxxxxx>
---
drivers/gpu/drm/i915/display/intel_connector.c | 11 ++++
drivers/gpu/drm/i915/display/intel_connector.h | 1 +
drivers/gpu/drm/i915/display/intel_display_types.h | 15 ++++++
drivers/gpu/drm/i915/display/intel_dp.c | 58 +++++++++++++++++-----
drivers/gpu/drm/i915/display/intel_dp.h | 4 ++
drivers/gpu/drm/i915/display/intel_dp_mst.c | 34 ++++++++++++-
drivers/gpu/drm/i915/display/intel_hdmi.c | 57 +++++++++++++++------
7 files changed, 152 insertions(+), 28 deletions(-)
diff --git a/drivers/gpu/drm/i915/display/intel_connector.c b/drivers/gpu/drm/i915/display/intel_connector.c
index 682bf1be350d..2d690e0400b5 100644
--- a/drivers/gpu/drm/i915/display/intel_connector.c
+++ b/drivers/gpu/drm/i915/display/intel_connector.c
@@ -38,6 +38,10 @@
#include "intel_hdcp.h"
#include "intel_panel.h"
+static const u32 supported_colorformats = DRM_COLOR_FORMAT_RGB444 |
+ DRM_COLOR_FORMAT_YCBCR444 |
+ DRM_COLOR_FORMAT_YCBCR420;
+
static void intel_connector_modeset_retry_work_fn(struct work_struct *work)
{
struct intel_connector *connector = container_of(work, typeof(*connector),
@@ -321,6 +325,13 @@ intel_attach_dp_colorspace_property(struct drm_connector *connector)
drm_connector_attach_colorspace_property(connector);
}
+void
+intel_attach_colorformat_property(struct drm_connector *connector)
+{
+ if (!drm_mode_create_color_format_property(connector, supported_colorformats))
+ drm_connector_attach_color_format_property(connector);
+}
+
void
intel_attach_scaling_mode_property(struct drm_connector *connector)
{
diff --git a/drivers/gpu/drm/i915/display/intel_connector.h b/drivers/gpu/drm/i915/display/intel_connector.h
index 0aa86626e646..fe6149d1d559 100644
--- a/drivers/gpu/drm/i915/display/intel_connector.h
+++ b/drivers/gpu/drm/i915/display/intel_connector.h
@@ -31,6 +31,7 @@ void intel_attach_broadcast_rgb_property(struct drm_connector *connector);
void intel_attach_aspect_ratio_property(struct drm_connector *connector);
void intel_attach_hdmi_colorspace_property(struct drm_connector *connector);
void intel_attach_dp_colorspace_property(struct drm_connector *connector);
+void intel_attach_colorformat_property(struct drm_connector *connector);
void intel_attach_scaling_mode_property(struct drm_connector *connector);
void intel_connector_queue_modeset_retry_work(struct intel_connector *connector);
void intel_connector_cancel_modeset_retry_work(struct intel_connector *connector);
diff --git a/drivers/gpu/drm/i915/display/intel_display_types.h b/drivers/gpu/drm/i915/display/intel_display_types.h
index e8e4af03a6a6..c230a545f95a 100644
--- a/drivers/gpu/drm/i915/display/intel_display_types.h
+++ b/drivers/gpu/drm/i915/display/intel_display_types.h
@@ -2252,6 +2252,21 @@ to_intel_frontbuffer(struct drm_framebuffer *fb)
return fb ? to_intel_framebuffer(fb)->frontbuffer : NULL;
}
+static inline __pure enum drm_color_format_enum
+intel_output_format_to_drm_color_format(enum intel_output_format input)
+{
+ switch (input) {
+ case INTEL_OUTPUT_FORMAT_RGB:
+ return DRM_COLOR_FORMAT_ENUM_RGB444;
+ case INTEL_OUTPUT_FORMAT_YCBCR444:
+ return DRM_COLOR_FORMAT_ENUM_YCBCR444;
+ case INTEL_OUTPUT_FORMAT_YCBCR420:
+ return DRM_COLOR_FORMAT_ENUM_YCBCR420;
+ default:
+ return DRM_COLOR_FORMAT_ENUM_INVALID;
+ }
+}
+
/*
* Conversion functions/macros from various pointer types to struct
* intel_display pointer.
diff --git a/drivers/gpu/drm/i915/display/intel_dp.c b/drivers/gpu/drm/i915/display/intel_dp.c
index b5fe7d8ba586..bc89aa5fdf01 100644
--- a/drivers/gpu/drm/i915/display/intel_dp.c
+++ b/drivers/gpu/drm/i915/display/intel_dp.c
@@ -1178,7 +1178,7 @@ dfp_can_convert(struct intel_dp *intel_dp,
return false;
}
-static enum intel_output_format
+enum intel_output_format
intel_dp_output_format(struct intel_connector *connector,
enum intel_output_format sink_format)
{
@@ -3319,17 +3319,24 @@ intel_dp_compute_output_format(struct intel_encoder *encoder,
struct intel_connector *connector = intel_dp->attached_connector;
const struct drm_display_info *info = &connector->base.display_info;
const struct drm_display_mode *adjusted_mode = &crtc_state->hw.adjusted_mode;
- bool ycbcr_420_only;
+ enum drm_color_format_enum sink_format_drm;
int ret;
- ycbcr_420_only = drm_mode_is_420_only(info, adjusted_mode);
+ if ((conn_state->color_format == DRM_COLOR_FORMAT_ENUM_YCBCR420 &&
+ drm_mode_is_420(info, adjusted_mode)) ||
+ (conn_state->color_format == DRM_COLOR_FORMAT_ENUM_AUTO &&
+ drm_mode_is_420_only(info, adjusted_mode)))
+ crtc_state->sink_format = INTEL_OUTPUT_FORMAT_YCBCR420;
+ else if (conn_state->color_format == DRM_COLOR_FORMAT_ENUM_YCBCR444)
+ crtc_state->sink_format = INTEL_OUTPUT_FORMAT_YCBCR444;
+ else
+ crtc_state->sink_format = INTEL_OUTPUT_FORMAT_RGB;
- if (ycbcr_420_only && !connector->base.ycbcr_420_allowed) {
+ if (crtc_state->sink_format == INTEL_OUTPUT_FORMAT_YCBCR420 &&
+ !connector->base.ycbcr_420_allowed) {
drm_dbg_kms(display->drm,
- "YCbCr 4:2:0 mode but YCbCr 4:2:0 output not possible. Falling back to RGB.\n");
- crtc_state->sink_format = INTEL_OUTPUT_FORMAT_RGB;
- } else {
- crtc_state->sink_format = intel_dp_sink_format(connector, adjusted_mode);
+ "YCbCr 4:2:0 mode requested but unsupported by connector.\n");
+ return -EINVAL;
}
crtc_state->output_format = intel_dp_output_format(connector, crtc_state->sink_format);
@@ -3337,9 +3344,20 @@ intel_dp_compute_output_format(struct intel_encoder *encoder,
ret = intel_dp_compute_link_config(encoder, crtc_state, conn_state,
respect_downstream_limits);
if (ret) {
- if (crtc_state->sink_format == INTEL_OUTPUT_FORMAT_YCBCR420 ||
- !connector->base.ycbcr_420_allowed ||
- !drm_mode_is_420_also(info, adjusted_mode))
+ /*
+ * If no valid link config can be found due to bandwidth constraints,
+ * degrade from RGB/YCbCr 4:4:4 to YCbCr 4:2:0 if permitted by
+ * the source and sink.
+ */
+ if (!connector->base.ycbcr_420_allowed)
+ return ret;
+ /* No point in trying YCbCr420 a second time. */
+ if (crtc_state->sink_format == INTEL_OUTPUT_FORMAT_YCBCR420)
+ return ret;
+ if (!drm_mode_is_420(info, adjusted_mode))
+ return ret;
+ /* If a non-AUTO color format is chosen, don't fall back. */
+ if (conn_state->color_format)
return ret;
crtc_state->sink_format = INTEL_OUTPUT_FORMAT_YCBCR420;
@@ -3347,9 +3365,23 @@ intel_dp_compute_output_format(struct intel_encoder *encoder,
crtc_state->sink_format);
ret = intel_dp_compute_link_config(encoder, crtc_state, conn_state,
respect_downstream_limits);
+ if (ret)
+ return ret;
}
- return ret;
+ sink_format_drm = intel_output_format_to_drm_color_format(crtc_state->sink_format);
+ if (sink_format_drm == DRM_COLOR_FORMAT_ENUM_INVALID)
+ return -EINVAL;
+
+ if (conn_state->color_format && conn_state->color_format != sink_format_drm) {
+ drm_dbg_kms(display->drm,
+ "Explicitly asked for color format %s, got sink format %s\n",
+ drm_get_color_format_name(conn_state->color_format),
+ drm_get_color_format_name(sink_format_drm));
+ return -EINVAL;
+ }
+
+ return 0;
}
void
@@ -6823,6 +6855,8 @@ intel_dp_add_properties(struct intel_dp *intel_dp, struct drm_connector *_connec
intel_attach_dp_colorspace_property(&connector->base);
}
+ intel_attach_colorformat_property(&connector->base);
+
if (intel_dp_has_gamut_metadata_dip(&dp_to_dig_port(intel_dp)->base))
drm_connector_attach_hdr_output_metadata_property(&connector->base);
diff --git a/drivers/gpu/drm/i915/display/intel_dp.h b/drivers/gpu/drm/i915/display/intel_dp.h
index cbd7fcd3789f..99aa0048a6c2 100644
--- a/drivers/gpu/drm/i915/display/intel_dp.h
+++ b/drivers/gpu/drm/i915/display/intel_dp.h
@@ -201,6 +201,10 @@ bool intel_dp_compute_config_limits(struct intel_dp *intel_dp,
void intel_dp_get_dsc_sink_cap(u8 dpcd_rev,
const struct drm_dp_desc *desc, bool is_branch,
struct intel_connector *connector);
+enum intel_output_format
+intel_dp_output_format(struct intel_connector *connector,
+ enum intel_output_format sink_format);
+
bool intel_dp_has_gamut_metadata_dip(struct intel_encoder *encoder);
bool intel_dp_link_params_valid(struct intel_dp *intel_dp, int link_rate,
diff --git a/drivers/gpu/drm/i915/display/intel_dp_mst.c b/drivers/gpu/drm/i915/display/intel_dp_mst.c
index 29713075e413..5b2297674ba4 100644
--- a/drivers/gpu/drm/i915/display/intel_dp_mst.c
+++ b/drivers/gpu/drm/i915/display/intel_dp_mst.c
@@ -706,6 +706,8 @@ static int mst_stream_compute_config(struct intel_encoder *encoder,
to_intel_connector(conn_state->connector);
const struct drm_display_mode *adjusted_mode =
&pipe_config->hw.adjusted_mode;
+ const struct drm_display_info *info =
+ &connector->base.display_info;
int num_joined_pipes;
int ret = -EINVAL;
@@ -716,8 +718,31 @@ static int mst_stream_compute_config(struct intel_encoder *encoder,
if (adjusted_mode->flags & DRM_MODE_FLAG_DBLSCAN)
return -EINVAL;
- pipe_config->sink_format = INTEL_OUTPUT_FORMAT_RGB;
- pipe_config->output_format = INTEL_OUTPUT_FORMAT_RGB;
+ if ((conn_state->color_format == DRM_COLOR_FORMAT_ENUM_YCBCR420 &&
+ drm_mode_is_420(info, adjusted_mode)) ||
+ (conn_state->color_format == DRM_COLOR_FORMAT_ENUM_AUTO &&
+ drm_mode_is_420_only(info, adjusted_mode))) {
+ pipe_config->sink_format = INTEL_OUTPUT_FORMAT_YCBCR420;
+ } else if (conn_state->color_format == DRM_COLOR_FORMAT_ENUM_YCBCR444) {
+ pipe_config->sink_format = INTEL_OUTPUT_FORMAT_YCBCR444;
+ } else if (conn_state->color_format == DRM_COLOR_FORMAT_ENUM_AUTO ||
+ conn_state->color_format == DRM_COLOR_FORMAT_RGB444) {
+ pipe_config->sink_format = INTEL_OUTPUT_FORMAT_RGB;
+ } else {
+ drm_dbg_kms(display->drm,
+ "Requested format %s unsupported.\n",
+ drm_get_color_format_name(conn_state->color_format));
+ return -EINVAL;
+ }
+
+ if (pipe_config->sink_format == INTEL_OUTPUT_FORMAT_YCBCR420 &&
+ !connector->base.ycbcr_420_allowed) {
+ drm_dbg_kms(display->drm,
+ "YCbCr 4:2:0 mode requested but unsupported by connector.\n");
+ return -EINVAL;
+ }
+
+ pipe_config->output_format = intel_dp_output_format(connector, pipe_config->sink_format);
pipe_config->has_pch_encoder = false;
for_each_joiner_candidate(connector, adjusted_mode, num_joined_pipes) {
@@ -1676,6 +1701,11 @@ static int mst_topology_add_connector_properties(struct intel_dp *intel_dp,
if (connector->base.max_bpc_property)
drm_connector_attach_max_bpc_property(&connector->base, 6, 12);
+ connector->base.color_format_property =
+ intel_dp->attached_connector->base.color_format_property;
+ if (connector->base.color_format_property)
+ intel_attach_colorformat_property(&connector->base);
+
return drm_connector_set_path_property(&connector->base, pathprop);
}
diff --git a/drivers/gpu/drm/i915/display/intel_hdmi.c b/drivers/gpu/drm/i915/display/intel_hdmi.c
index 05e898d10a2b..ff5ebf4b9508 100644
--- a/drivers/gpu/drm/i915/display/intel_hdmi.c
+++ b/drivers/gpu/drm/i915/display/intel_hdmi.c
@@ -2270,30 +2270,57 @@ static int intel_hdmi_compute_output_format(struct intel_encoder *encoder,
struct intel_connector *connector = to_intel_connector(conn_state->connector);
const struct drm_display_mode *adjusted_mode = &crtc_state->hw.adjusted_mode;
const struct drm_display_info *info = &connector->base.display_info;
- bool ycbcr_420_only = drm_mode_is_420_only(info, adjusted_mode);
+ enum drm_color_format_enum req_fmt = conn_state->color_format;
+ enum drm_color_format_enum sink_format_drm;
int ret;
- crtc_state->sink_format =
- intel_hdmi_sink_format(crtc_state, connector, ycbcr_420_only);
-
- if (ycbcr_420_only && crtc_state->sink_format != INTEL_OUTPUT_FORMAT_YCBCR420) {
- drm_dbg_kms(display->drm,
- "YCbCr 4:2:0 mode but YCbCr 4:2:0 output not possible. Falling back to RGB.\n");
- crtc_state->sink_format = INTEL_OUTPUT_FORMAT_RGB;
- }
+ if (!req_fmt)
+ crtc_state->sink_format =
+ intel_hdmi_sink_format(crtc_state, connector,
+ drm_mode_is_420_only(info, adjusted_mode));
+ else if (req_fmt == DRM_COLOR_FORMAT_ENUM_YCBCR444)
+ crtc_state->sink_format = INTEL_OUTPUT_FORMAT_YCBCR444;
+ else
+ crtc_state->sink_format =
+ intel_hdmi_sink_format(crtc_state, connector,
+ req_fmt == DRM_COLOR_FORMAT_ENUM_YCBCR420);
crtc_state->output_format = intel_hdmi_output_format(crtc_state);
ret = intel_hdmi_compute_clock(encoder, crtc_state, respect_downstream_limits);
if (ret) {
- if (crtc_state->sink_format == INTEL_OUTPUT_FORMAT_YCBCR420 ||
- !crtc_state->has_hdmi_sink ||
- !connector->base.ycbcr_420_allowed ||
- !drm_mode_is_420_also(info, adjusted_mode))
+ /*
+ * If no valid link config can be found due to bandwidth constraints,
+ * degrade from RGB/YCbCr 4:4:4 to YCbCr 4:2:0 if permitted by
+ * the source and sink.
+ */
+ if (!connector->base.ycbcr_420_allowed)
+ return ret;
+ /* No point in trying YCbCr420 a second time. */
+ if (crtc_state->sink_format == INTEL_OUTPUT_FORMAT_YCBCR420)
+ return ret;
+ if (!drm_mode_is_420(info, adjusted_mode))
+ return ret;
+ /* If a non-AUTO color format is chosen, don't fall back. */
+ if (req_fmt)
return ret;
crtc_state->sink_format = INTEL_OUTPUT_FORMAT_YCBCR420;
crtc_state->output_format = intel_hdmi_output_format(crtc_state);
ret = intel_hdmi_compute_clock(encoder, crtc_state, respect_downstream_limits);
+ if (ret)
+ return ret;
+ }
+
+ sink_format_drm = intel_output_format_to_drm_color_format(crtc_state->sink_format);
+ if (sink_format_drm == DRM_COLOR_FORMAT_ENUM_INVALID)
+ return -EINVAL;
+
+ if (req_fmt && req_fmt != sink_format_drm) {
+ drm_dbg_kms(display->drm,
+ "Explicitly asked for color format %s, got sink format %s\n",
+ drm_get_color_format_name(req_fmt),
+ drm_get_color_format_name(sink_format_drm));
+ ret = -EINVAL;
}
return ret;
@@ -2689,8 +2716,10 @@ intel_hdmi_add_properties(struct intel_hdmi *intel_hdmi, struct drm_connector *_
if (DISPLAY_VER(display) >= 10)
drm_connector_attach_hdr_output_metadata_property(&connector->base);
- if (!HAS_GMCH(display))
+ if (!HAS_GMCH(display)) {
drm_connector_attach_max_bpc_property(&connector->base, 8, 12);
+ intel_attach_colorformat_property(&connector->base);
+ }
}
/*
--
2.53.0