drm/i915/tgl: Select master transcoder for MST stream

On TGL the blending of all the streams have moved from DDI to
transcoder, so now every transcoder working over the same MST port must
send its stream to a master transcoder and master will send to DDI
respecting the time slots.

So here adding all the CRTCs that shares the same MST stream if
needed and computing their state again, it will pick the lowest
pipe/transcoder among the ones in the same stream to be master.

Most of the time skl_commit_modeset_enables() enables pipes in a
crescent order but due DDB overlapping it might not happen, this
scenarios will be handled in the next patch.

v2:
- Using recently added intel_crtc_state_reset() to set
mst_master_transcoder to invalid transcoder for all non gen12 & MST
code paths
- Setting lowest pipe/transcoder as master, previously it was the
first one but setting a predictable one will help in future MST e
port sync integration
- Moving to intel type as much as we can

v3:
- Now intel_dp_mst_master_trans_compute() returns the MST master transcoder
- Replaced stdbool.h by linux/types.h
- Skip the connector being checked in
intel_dp_mst_atomic_master_trans_check()
- Using pipe instead of transcoder to compute MST master

v4:
- renamed connector_state to conn_state

v5:
- Improved the parameters of intel_dp_mst_master_trans_compute() to
simply code
- Added call drm_atomic_add_affected_planes() in
intel_dp_mst_atomic_master_trans_check() as helper could not do it
for us
- Removed "if (ret)" left over from v3 changes

v6:
- handled ret == I915_MAX_PIPES case in compute

BSpec: 50493
BSpec: 49190
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: Lucas De Marchi <lucas.demarchi@intel.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: José Roberto de Souza <jose.souza@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20191223010654.67037-2-jose.souza@intel.com

drivers/gpu/drm/i915/display/intel_atomic.c

@@ -192,6 +192,20 @@ intel_connector_needs_modeset(struct intel_atomic_state *state,
 									    new_conn_state->crtc)));
 }
 
+struct intel_digital_connector_state *
+intel_atomic_get_digital_connector_state(struct intel_atomic_state *state,
+					 struct intel_connector *connector)
+{
+	struct drm_connector_state *conn_state;
+
+	conn_state = drm_atomic_get_connector_state(&state->base,
+						    &connector->base);
+	if (IS_ERR(conn_state))
+		return ERR_CAST(conn_state);
+
+	return to_intel_digital_connector_state(conn_state);
+}
+
 /**
  * intel_crtc_duplicate_state - duplicate crtc state
  * @crtc: drm crtc

drivers/gpu/drm/i915/display/intel_atomic.h

@@ -17,6 +17,7 @@ struct drm_device;
 struct drm_i915_private;
 struct drm_property;
 struct intel_atomic_state;
+struct intel_connector;
 struct intel_crtc;
 struct intel_crtc_state;
 
@@ -34,6 +35,9 @@ struct drm_connector_state *
 intel_digital_connector_duplicate_state(struct drm_connector *connector);
 bool intel_connector_needs_modeset(struct intel_atomic_state *state,
 				   struct drm_connector *connector);
+struct intel_digital_connector_state *
+intel_atomic_get_digital_connector_state(struct intel_atomic_state *state,
+					 struct intel_connector *connector);
 
 struct drm_crtc_state *intel_crtc_duplicate_state(struct drm_crtc *crtc);
 void intel_crtc_destroy_state(struct drm_crtc *crtc,

drivers/gpu/drm/i915/display/intel_ddi.c

@@ -1899,8 +1899,13 @@ intel_ddi_transcoder_func_reg_val_get(const struct intel_crtc_state *crtc_state)
 		temp |= TRANS_DDI_MODE_SELECT_DP_MST;
 		temp |= DDI_PORT_WIDTH(crtc_state->lane_count);
 
-		if (INTEL_GEN(dev_priv) >= 12)
-			temp |= TRANS_DDI_MST_TRANSPORT_SELECT(crtc_state->cpu_transcoder);
+		if (INTEL_GEN(dev_priv) >= 12) {
+			enum transcoder master;
+
+			master = crtc_state->mst_master_transcoder;
+			WARN_ON(master == INVALID_TRANSCODER);
+			temp |= TRANS_DDI_MST_TRANSPORT_SELECT(master);
+		}
 	} else {
 		temp |= TRANS_DDI_MODE_SELECT_DP_SST;
 		temp |= DDI_PORT_WIDTH(crtc_state->lane_count);
@@ -4405,6 +4410,11 @@ void intel_ddi_get_config(struct intel_encoder *encoder,
 		pipe_config->output_types |= BIT(INTEL_OUTPUT_DP_MST);
 		pipe_config->lane_count =
 			((temp & DDI_PORT_WIDTH_MASK) >> DDI_PORT_WIDTH_SHIFT) + 1;
+
+		if (INTEL_GEN(dev_priv) >= 12)
+			pipe_config->mst_master_transcoder =
+					REG_FIELD_GET(TRANS_DDI_MST_TRANSPORT_SELECT_MASK, temp);
+
 		intel_dp_get_m_n(intel_crtc, pipe_config);
 		break;
 	default:

drivers/gpu/drm/i915/display/intel_display.c

@@ -46,6 +46,7 @@
 #include "display/intel_crt.h"
 #include "display/intel_ddi.h"
 #include "display/intel_dp.h"
+#include "display/intel_dp_mst.h"
 #include "display/intel_dsi.h"
 #include "display/intel_dvo.h"
 #include "display/intel_gmbus.h"
@@ -11880,6 +11881,7 @@ static void intel_crtc_state_reset(struct intel_crtc_state *crtc_state,
 	crtc_state->hsw_workaround_pipe = INVALID_PIPE;
 	crtc_state->output_format = INTEL_OUTPUT_FORMAT_INVALID;
 	crtc_state->scaler_state.scaler_id = -1;
+	crtc_state->mst_master_transcoder = INVALID_TRANSCODER;
 }
 
 static struct intel_crtc_state *intel_crtc_state_alloc(struct intel_crtc *crtc)
@@ -12738,6 +12740,9 @@ static void intel_dump_pipe_config(const struct intel_crtc_state *pipe_config,
 			      pipe_config->csc_mode, pipe_config->gamma_mode,
 			      pipe_config->gamma_enable, pipe_config->csc_enable);
 
+	DRM_DEBUG_KMS("MST master transcoder: %s\n",
+		      transcoder_name(pipe_config->mst_master_transcoder));
+
 dump_planes:
 	if (!state)
 		return;
@@ -13518,6 +13523,8 @@ intel_pipe_config_compare(const struct intel_crtc_state *current_config,
 	PIPE_CONF_CHECK_I(dsc.dsc_split);
 	PIPE_CONF_CHECK_I(dsc.compressed_bpp);
 
+	PIPE_CONF_CHECK_I(mst_master_transcoder);
+
 #undef PIPE_CONF_CHECK_X
 #undef PIPE_CONF_CHECK_I
 #undef PIPE_CONF_CHECK_BOOL
@@ -14602,7 +14609,7 @@ static void intel_commit_modeset_disables(struct intel_atomic_state *state)
 	u32 handled = 0;
 	int i;
 
-	/* Only disable port sync slaves */
+	/* Only disable port sync and MST slaves */
 	for_each_oldnew_intel_crtc_in_state(state, crtc, old_crtc_state,
 					    new_crtc_state, i) {
 		if (!needs_modeset(new_crtc_state))
@@ -14616,7 +14623,8 @@ static void intel_commit_modeset_disables(struct intel_atomic_state *state)
 		 * slave CRTCs are disabled first and then master CRTC since
 		 * Slave vblanks are masked till Master Vblanks.
 		 */
-		if (!is_trans_port_sync_slave(old_crtc_state))
+		if (!is_trans_port_sync_slave(old_crtc_state) &&
+		    !intel_dp_mst_is_slave_trans(old_crtc_state))
 			continue;
 
 		intel_pre_plane_update(state, crtc);

drivers/gpu/drm/i915/display/intel_display_types.h

@@ -1054,6 +1054,9 @@ struct intel_crtc_state {
 
 	/* Bitmask to indicate slaves attached */
 	u8 sync_mode_slaves_mask;
+
+	/* Only valid on TGL+ */
+	enum transcoder mst_master_transcoder;
 };
 
 struct intel_crtc {

drivers/gpu/drm/i915/display/intel_dp_mst.c

@@ -87,10 +87,56 @@ static int intel_dp_mst_compute_link_config(struct intel_encoder *encoder,
 	return 0;
 }
 
+/*
+ * Iterate over all connectors and return the smallest transcoder in the MST
+ * stream
+ */
+static enum transcoder
+intel_dp_mst_master_trans_compute(struct intel_atomic_state *state,
+				  struct intel_dp *mst_port)
+{
+	struct drm_i915_private *dev_priv = to_i915(state->base.dev);
+	struct intel_digital_connector_state *conn_state;
+	struct intel_connector *connector;
+	enum pipe ret = I915_MAX_PIPES;
+	int i;
+
+	if (INTEL_GEN(dev_priv) < 12)
+		return INVALID_TRANSCODER;
+
+	for_each_new_intel_connector_in_state(state, connector, conn_state, i) {
+		struct intel_crtc_state *crtc_state;
+		struct intel_crtc *crtc;
+
+		if (connector->mst_port != mst_port || !conn_state->base.crtc)
+			continue;
+
+		crtc = to_intel_crtc(conn_state->base.crtc);
+		crtc_state = intel_atomic_get_new_crtc_state(state, crtc);
+		if (!crtc_state->uapi.active)
+			continue;
+
+		/*
+		 * Using crtc->pipe because crtc_state->cpu_transcoder is
+		 * computed, so others CRTCs could have non-computed
+		 * cpu_transcoder
+		 */
+		if (crtc->pipe < ret)
+			ret = crtc->pipe;
+	}
+
+	if (ret == I915_MAX_PIPES)
+		return INVALID_TRANSCODER;
+
+	/* Simple cast works because TGL don't have a eDP transcoder */
+	return (enum transcoder)ret;
+}
+
 static int intel_dp_mst_compute_config(struct intel_encoder *encoder,
 				       struct intel_crtc_state *pipe_config,
 				       struct drm_connector_state *conn_state)
 {
+	struct intel_atomic_state *state = to_intel_atomic_state(conn_state->state);
 	struct drm_i915_private *dev_priv = to_i915(encoder->base.dev);
 	struct intel_dp_mst_encoder *intel_mst = enc_to_mst(&encoder->base);
 	struct intel_dp *intel_dp = &intel_mst->primary->dp;
@@ -154,24 +200,91 @@ static int intel_dp_mst_compute_config(struct intel_encoder *encoder,
 
 	intel_ddi_compute_min_voltage_level(dev_priv, pipe_config);
 
+	pipe_config->mst_master_transcoder = intel_dp_mst_master_trans_compute(state, intel_dp);
+
+	return 0;
+}
+
+/*
+ * If one of the connectors in a MST stream needs a modeset, mark all CRTCs
+ * that shares the same MST stream as mode changed,
+ * intel_modeset_pipe_config()+intel_crtc_check_fastset() will take care to do
+ * a fastset when possible.
+ */
+static int
+intel_dp_mst_atomic_master_trans_check(struct intel_connector *connector,
+				       struct intel_atomic_state *state)
+{
+	struct drm_i915_private *dev_priv = to_i915(state->base.dev);
+	struct drm_connector_list_iter connector_list_iter;
+	struct intel_connector *connector_iter;
+
+	if (INTEL_GEN(dev_priv) < 12)
+		return  0;
+
+	if (!intel_connector_needs_modeset(state, &connector->base))
+		return 0;
+
+	drm_connector_list_iter_begin(&dev_priv->drm, &connector_list_iter);
+	for_each_intel_connector_iter(connector_iter, &connector_list_iter) {
+		struct intel_digital_connector_state *conn_iter_state;
+		struct intel_crtc_state *crtc_state;
+		struct intel_crtc *crtc;
+		int ret;
+
+		if (connector_iter->mst_port != connector->mst_port ||
+		    connector_iter == connector)
+			continue;
+
+		conn_iter_state = intel_atomic_get_digital_connector_state(state,
+									   connector_iter);
+		if (IS_ERR(conn_iter_state)) {
+			drm_connector_list_iter_end(&connector_list_iter);
+			return PTR_ERR(conn_iter_state);
+		}
+
+		if (!conn_iter_state->base.crtc)
+			continue;
+
+		crtc = to_intel_crtc(conn_iter_state->base.crtc);
+		crtc_state = intel_atomic_get_crtc_state(&state->base, crtc);
+		if (IS_ERR(crtc_state)) {
+			drm_connector_list_iter_end(&connector_list_iter);
+			return PTR_ERR(crtc_state);
+		}
+
+		ret = drm_atomic_add_affected_planes(&state->base, &crtc->base);
+		if (ret) {
+			drm_connector_list_iter_end(&connector_list_iter);
+			return ret;
+		}
+		crtc_state->uapi.mode_changed = true;
+	}
+	drm_connector_list_iter_end(&connector_list_iter);
+
 	return 0;
 }
 
 static int
 intel_dp_mst_atomic_check(struct drm_connector *connector,
-			  struct drm_atomic_state *state)
+			  struct drm_atomic_state *_state)
 {
+	struct intel_atomic_state *state = to_intel_atomic_state(_state);
 	struct drm_connector_state *new_conn_state =
-		drm_atomic_get_new_connector_state(state, connector);
+		drm_atomic_get_new_connector_state(&state->base, connector);
 	struct drm_connector_state *old_conn_state =
-		drm_atomic_get_old_connector_state(state, connector);
+		drm_atomic_get_old_connector_state(&state->base, connector);
 	struct intel_connector *intel_connector =
 		to_intel_connector(connector);
 	struct drm_crtc *new_crtc = new_conn_state->crtc;
 	struct drm_dp_mst_topology_mgr *mgr;
 	int ret;
 
-	ret = intel_digital_connector_atomic_check(connector, state);
+	ret = intel_digital_connector_atomic_check(connector, &state->base);
+	if (ret)
+		return ret;
+
+	ret = intel_dp_mst_atomic_master_trans_check(intel_connector, state);
 	if (ret)
 		return ret;
 
@@ -182,12 +295,9 @@ intel_dp_mst_atomic_check(struct drm_connector *connector,
 	 * connector
 	 */
 	if (new_crtc) {
-		struct intel_atomic_state *intel_state =
-			to_intel_atomic_state(state);
 		struct intel_crtc *intel_crtc = to_intel_crtc(new_crtc);
 		struct intel_crtc_state *crtc_state =
-			intel_atomic_get_new_crtc_state(intel_state,
-							intel_crtc);
+			intel_atomic_get_new_crtc_state(state, intel_crtc);
 
 		if (!crtc_state ||
 		    !drm_atomic_crtc_needs_modeset(&crtc_state->uapi) ||
@@ -196,7 +306,7 @@ intel_dp_mst_atomic_check(struct drm_connector *connector,
 	}
 
 	mgr = &enc_to_mst(old_conn_state->best_encoder)->primary->dp.mst_mgr;
-	ret = drm_dp_atomic_release_vcpi_slots(state, mgr,
+	ret = drm_dp_atomic_release_vcpi_slots(&state->base, mgr,
 					       intel_connector->port);
 
 	return ret;
@@ -240,6 +350,8 @@ static void intel_mst_post_disable_dp(struct intel_encoder *encoder,
 
 	intel_dp->active_mst_links--;
 	last_mst_stream = intel_dp->active_mst_links == 0;
+	WARN_ON(INTEL_GEN(dev_priv) >= 12 && last_mst_stream &&
+		!intel_dp_mst_is_master_trans(old_crtc_state));
 
 	intel_crtc_vblank_off(old_crtc_state);
 
@@ -317,6 +429,8 @@ static void intel_mst_pre_enable_dp(struct intel_encoder *encoder,
 	connector->encoder = encoder;
 	intel_mst->connector = connector;
 	first_mst_stream = intel_dp->active_mst_links == 0;
+	WARN_ON(INTEL_GEN(dev_priv) >= 12 && first_mst_stream &&
+		!intel_dp_mst_is_master_trans(pipe_config));
 
 	DRM_DEBUG_KMS("active links %d\n", intel_dp->active_mst_links);
 
@@ -722,3 +836,14 @@ intel_dp_mst_encoder_cleanup(struct intel_digital_port *intel_dig_port)
 	drm_dp_mst_topology_mgr_destroy(&intel_dp->mst_mgr);
 	/* encoders will get killed by normal cleanup */
 }
+
+bool intel_dp_mst_is_master_trans(const struct intel_crtc_state *crtc_state)
+{
+	return crtc_state->mst_master_transcoder == crtc_state->cpu_transcoder;
+}
+
+bool intel_dp_mst_is_slave_trans(const struct intel_crtc_state *crtc_state)
+{
+	return crtc_state->mst_master_transcoder != INVALID_TRANSCODER &&
+	       crtc_state->mst_master_transcoder != crtc_state->cpu_transcoder;
+}

drivers/gpu/drm/i915/display/intel_dp_mst.h

@@ -6,10 +6,15 @@
 #ifndef __INTEL_DP_MST_H__
 #define __INTEL_DP_MST_H__
 
+#include <linux/types.h>
+
 struct intel_digital_port;
+struct intel_crtc_state;
 
 int intel_dp_mst_encoder_init(struct intel_digital_port *intel_dig_port, int conn_id);
 void intel_dp_mst_encoder_cleanup(struct intel_digital_port *intel_dig_port);
 int intel_dp_mst_encoder_active_links(struct intel_digital_port *intel_dig_port);
+bool intel_dp_mst_is_master_trans(const struct intel_crtc_state *crtc_state);
+bool intel_dp_mst_is_slave_trans(const struct intel_crtc_state *crtc_state);
 
 #endif /* __INTEL_DP_MST_H__ */