[Intel-gfx] [PATCH v2 6/6] drm/i915: Set DP min_bpp to 8*3 for non-RGB output formats

[Ville Syrjala]

From: Ville Syrjälä <ville.syrjala at linux.intel.com>

6bpc is only legal for RGB and RAW pixel encodings. For the rest
the minimum is 8bpc. Set our lower limit accordingly.

Signed-off-by: Ville Syrjälä <ville.syrjala at linux.intel.com>
---
 drivers/gpu/drm/i915/intel_dp.c     | 10 +++++++++-
 drivers/gpu/drm/i915/intel_dp_mst.c |  2 +-
 drivers/gpu/drm/i915/intel_drv.h    |  1 +
 3 files changed, 11 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
index 2aee526ed632..149fdfbcb343 100644
--- a/drivers/gpu/drm/i915/intel_dp.c
+++ b/drivers/gpu/drm/i915/intel_dp.c
@@ -2002,6 +2002,14 @@ static int intel_dp_dsc_compute_config(struct intel_dp *intel_dp,
 	return 0;
 }
 
+int intel_dp_min_bpp(const struct intel_crtc_state *crtc_state)
+{
+	if (crtc_state->output_format == INTEL_OUTPUT_FORMAT_RGB)
+		return 6 * 3;
+	else
+		return 8 * 3;
+}
+
 static int
 intel_dp_compute_link_config(struct intel_encoder *encoder,
 			     struct intel_crtc_state *pipe_config,
@@ -2025,7 +2033,7 @@ intel_dp_compute_link_config(struct intel_encoder *encoder,
 	limits.min_lane_count = 1;
 	limits.max_lane_count = intel_dp_max_lane_count(intel_dp);
 
-	limits.min_bpp = 6 * 3;
+	limits.min_bpp = intel_dp_min_bpp(pipe_config);
 	limits.max_bpp = intel_dp_compute_bpp(intel_dp, pipe_config);
 
 	if (intel_dp_is_edp(intel_dp) && intel_dp->edp_dpcd[0] < DP_EDP_14) {
diff --git a/drivers/gpu/drm/i915/intel_dp_mst.c b/drivers/gpu/drm/i915/intel_dp_mst.c
index 6d2af7cf48e6..79c229184873 100644
--- a/drivers/gpu/drm/i915/intel_dp_mst.c
+++ b/drivers/gpu/drm/i915/intel_dp_mst.c
@@ -119,7 +119,7 @@ static int intel_dp_mst_compute_config(struct intel_encoder *encoder,
 	limits.min_lane_count =
 	limits.max_lane_count = intel_dp_max_lane_count(intel_dp);
 
-	limits.min_bpp = 6 * 3;
+	limits.min_bpp = intel_dp_min_bpp(pipe_config);
 	limits.max_bpp = pipe_config->pipe_bpp;
 
 	intel_dp_adjust_compliance_config(intel_dp, pipe_config, &limits);
diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
index e79954c6271c..13f1b0367287 100644
--- a/drivers/gpu/drm/i915/intel_drv.h
+++ b/drivers/gpu/drm/i915/intel_drv.h
@@ -1919,6 +1919,7 @@ void intel_dp_adjust_compliance_config(struct intel_dp *intel_dp,
 				       struct link_config_limits *limits);
 bool intel_dp_limited_color_range(const struct intel_crtc_state *crtc_state,
 				  const struct drm_connector_state *conn_state);
+int intel_dp_min_bpp(const struct intel_crtc_state *crtc_state);
 bool intel_dp_port_enabled(struct drm_i915_private *dev_priv,
 			   i915_reg_t dp_reg, enum port port,
 			   enum pipe *pipe);
-- 
2.19.2