[PATCH v6 2/2] drm/i915: Allow "max bpc" property to limit pipe_bpp

[Radhakrishna Sripada]

Use the newly added "max bpc" connector property to limit pipe bpp.

V3: Use drm_connector_state to access the "max bpc" property
V4: Initialize the drm property, add suuport to DP(Ville)
V5: Use the property in the connector and fix CI failure(Ville)
V6: Use the core function to attach max_bpc property, remove the redundant
    clamping of pipe bpp based on connector info

Cc: Ville Syrjälä <ville.syrjala at linux.intel.com>
Cc: Daniel Vetter <daniel.vetter at iffwll.ch>
Cc: Rodrigo Vivi <rodrigo.vivi at intel.com>
Cc: Kishore Kadiyala <kishore.kadiyala at intel.com>
Cc: Manasi Navare <manasi.d.navare at intel.com>
Cc: Stanislav Lisovskiy <stanislav.lisovskiy at intel.com>
Signed-off-by: Radhakrishna Sripada <radhakrishna.sripada at intel.com>
---
 drivers/gpu/drm/i915/intel_display.c | 49 ++++++++++++++++++++----------------
 drivers/gpu/drm/i915/intel_dp.c      |  5 ++++
 drivers/gpu/drm/i915/intel_hdmi.c    |  5 ++++
 3 files changed, 38 insertions(+), 21 deletions(-)

diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index eb25037d7b38..219323f6b16e 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -10845,29 +10845,37 @@ static void intel_modeset_update_connector_atomic_state(struct drm_device *dev)
 }
 
 static void
-connected_sink_compute_bpp(struct intel_connector *connector,
-			   struct intel_crtc_state *pipe_config)
+connected_sink_max_bpp(struct drm_connector_state *conn_state,
+		       struct intel_crtc_state *pipe_config)
 {
-	const struct drm_display_info *info = &connector->base.display_info;
-	int bpp = pipe_config->pipe_bpp;
-
-	DRM_DEBUG_KMS("[CONNECTOR:%d:%s] checking for sink bpp constrains\n",
-		      connector->base.base.id,
-		      connector->base.name);
-
-	/* Don't use an invalid EDID bpc value */
-	if (info->bpc != 0 && info->bpc * 3 < bpp) {
-		DRM_DEBUG_KMS("clamping display bpp (was %d) to EDID reported max of %d\n",
-			      bpp, info->bpc * 3);
-		pipe_config->pipe_bpp = info->bpc * 3;
+	if (pipe_config->pipe_bpp < conn_state->max_bpc * 3) {
+		conn_state->max_bpc = pipe_config->pipe_bpp / 3;
+		return;
 	}
 
-	/* Clamp bpp to 8 on screens without EDID 1.4 */
-	if (info->bpc == 0 && bpp > 24) {
-		DRM_DEBUG_KMS("clamping display bpp (was %d) to default limit of 24\n",
-			      bpp);
-		pipe_config->pipe_bpp = 24;
+	switch (conn_state->max_bpc) {
+	case 8:
+	case 9:
+		pipe_config->pipe_bpp = 8*3;
+		break;
+	case 10:
+	case 11:
+		pipe_config->pipe_bpp = 10*3;
+		break;
+	case 12:
+	case 13:
+	case 14:
+	case 15:
+		pipe_config->pipe_bpp = 12*3;
+		break;
+	case 16:
+		pipe_config->pipe_bpp = 16*3;
+		break;
+	default:
+		break;
 	}
+
+	DRM_DEBUG_KMS("Limiting display bpp to %d\n", pipe_config->pipe_bpp);
 }
 
 static int
@@ -10898,8 +10906,7 @@ compute_baseline_pipe_bpp(struct intel_crtc *crtc,
 		if (connector_state->crtc != &crtc->base)
 			continue;
 
-		connected_sink_compute_bpp(to_intel_connector(connector),
-					   pipe_config);
+		connected_sink_max_bpp(connector_state, pipe_config);
 	}
 
 	return bpp;
diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
index 436c22de33b6..aefca1d9e87b 100644
--- a/drivers/gpu/drm/i915/intel_dp.c
+++ b/drivers/gpu/drm/i915/intel_dp.c
@@ -5719,6 +5719,11 @@ intel_dp_add_properties(struct intel_dp *intel_dp, struct drm_connector *connect
 		intel_attach_force_audio_property(connector);
 
 	intel_attach_broadcast_rgb_property(connector);
+	if ((IS_G4X(dev_priv) || IS_VALLEYVIEW(dev_priv) ||
+	     IS_CHERRYVIEW(dev_priv)))
+		drm_connector_attach_max_bpc_property(connector, 8, 10);
+	else if (INTEL_GEN(dev_priv) >= 5)
+		drm_connector_attach_max_bpc_property(connector, 8, 12);
 
 	if (intel_dp_is_edp(intel_dp)) {
 		u32 allowed_scalers;
diff --git a/drivers/gpu/drm/i915/intel_hdmi.c b/drivers/gpu/drm/i915/intel_hdmi.c
index a2dab0b6bde6..2b432c7e4f8a 100644
--- a/drivers/gpu/drm/i915/intel_hdmi.c
+++ b/drivers/gpu/drm/i915/intel_hdmi.c
@@ -2109,11 +2109,16 @@ static const struct drm_encoder_funcs intel_hdmi_enc_funcs = {
 static void
 intel_hdmi_add_properties(struct intel_hdmi *intel_hdmi, struct drm_connector *connector)
 {
+	struct drm_i915_private *dev_priv = to_i915(connector->dev);
+
 	intel_attach_force_audio_property(connector);
 	intel_attach_broadcast_rgb_property(connector);
 	intel_attach_aspect_ratio_property(connector);
 	drm_connector_attach_content_type_property(connector);
 	connector->state->picture_aspect_ratio = HDMI_PICTURE_ASPECT_NONE;
+
+	if (!HAS_GMCH_DISPLAY(dev_priv))
+		drm_connector_attach_max_bpc_property(connector, 8, 12);
 }
 
 /*
-- 
2.9.3