[Intel-gfx] [PATCH 1/4] drm/i915/tgl: Select master transcoder for MST stream

["José Roberto de Souza" <jose.souza@intel.com>]

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 first
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
scenario will be handled in the next patch.

BSpec: 50493
BSpec: 49190
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: Lucas De Marchi <lucas.demarchi@intel.com>
Signed-off-by: José Roberto de Souza <jose.souza@intel.com>
---
 drivers/gpu/drm/i915/display/intel_ddi.c      |  14 +-
 drivers/gpu/drm/i915/display/intel_display.c  |  15 +-
 .../drm/i915/display/intel_display_types.h    |   3 +
 drivers/gpu/drm/i915/display/intel_dp_mst.c   | 163 ++++++++++++++++++
 drivers/gpu/drm/i915/display/intel_dp_mst.h   |   5 +
 5 files changed, 196 insertions(+), 4 deletions(-)

diff --git a/drivers/gpu/drm/i915/display/intel_ddi.c b/drivers/gpu/drm/i915/display/intel_ddi.c
index 3cacb1e279c1..be5bc506d4d3 100644
--- a/drivers/gpu/drm/i915/display/intel_ddi.c
+++ b/drivers/gpu/drm/i915/display/intel_ddi.c
@@ -1903,8 +1903,13 @@ 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);
@@ -4372,6 +4377,11 @@ 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:
diff --git a/drivers/gpu/drm/i915/display/intel_display.c b/drivers/gpu/drm/i915/display/intel_display.c
index 821ba8053f9d..f89494c849ce 100644
--- a/drivers/gpu/drm/i915/display/intel_display.c
+++ b/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"
@@ -12542,6 +12543,11 @@ 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);
 
+	if (INTEL_GEN(dev_priv) >= 12 &&
+	    intel_crtc_has_type(pipe_config, INTEL_OUTPUT_DP_MST))
+		DRM_DEBUG_KMS("MST master transcoder: %s\n",
+			      transcoder_name(pipe_config->mst_master_transcoder));
+
 dump_planes:
 	if (!state)
 		return;
@@ -13318,6 +13324,10 @@ intel_pipe_config_compare(const struct intel_crtc_state *current_config,
 	PIPE_CONF_CHECK_I(sync_mode_slaves_mask);
 	PIPE_CONF_CHECK_I(master_transcoder);
 
+	if (INTEL_GEN(dev_priv) >= 12 &&
+	    intel_crtc_has_type(pipe_config, INTEL_OUTPUT_DP_MST))
+		PIPE_CONF_CHECK_I(mst_master_transcoder);
+
 #undef PIPE_CONF_CHECK_X
 #undef PIPE_CONF_CHECK_I
 #undef PIPE_CONF_CHECK_BOOL
@@ -14406,7 +14416,7 @@ 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))
@@ -14420,7 +14430,8 @@ 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);
diff --git a/drivers/gpu/drm/i915/display/intel_display_types.h b/drivers/gpu/drm/i915/display/intel_display_types.h
index 83ea04149b77..630a94892b7b 100644
--- a/drivers/gpu/drm/i915/display/intel_display_types.h
+++ b/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 {
diff --git a/drivers/gpu/drm/i915/display/intel_dp_mst.c b/drivers/gpu/drm/i915/display/intel_dp_mst.c
index 926e49f449a6..49f1518e3ab9 100644
--- a/drivers/gpu/drm/i915/display/intel_dp_mst.c
+++ b/drivers/gpu/drm/i915/display/intel_dp_mst.c
@@ -87,6 +87,49 @@ static int intel_dp_mst_compute_link_config(struct intel_encoder *encoder,
 	return 0;
 }
 
+/*
+ * Iterate over all the CRTCs and set mst_master_transcoder to the first active
+ * transcoder that shares the same MST connector.
+ *
+ * TODO: maybe this could be optimized to keep the old master transcoder
+ */
+static int
+intel_dp_mst_master_trans_compute(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(pipe_config->uapi.state);
+	struct intel_connector *conn = to_intel_connector(conn_state->connector);
+	struct drm_i915_private *dev_priv = to_i915(encoder->base.dev);
+	struct intel_digital_connector_state *iter_conn_state;
+	struct intel_connector *iter_conn;
+	int i;
+
+	if (INTEL_GEN(dev_priv) < 12)
+		return 0;
+
+	for_each_new_intel_connector_in_state(state, iter_conn,
+					      iter_conn_state, i) {
+		struct intel_crtc_state *iter_crtc_state;
+		struct intel_crtc *iter_crtc;
+
+		if (conn->mst_port != iter_conn->mst_port ||
+		    !iter_conn_state->base.crtc)
+			continue;
+
+		iter_crtc = to_intel_crtc(iter_conn_state->base.crtc);
+		iter_crtc_state = intel_atomic_get_new_crtc_state(state,
+								  iter_crtc);
+		if (!iter_crtc_state->uapi.active)
+			continue;
+
+		pipe_config->mst_master_transcoder = iter_crtc_state->cpu_transcoder;
+		break;
+	}
+
+	return 0;
+}
+
 static int intel_dp_mst_compute_config(struct intel_encoder *encoder,
 				       struct intel_crtc_state *pipe_config,
 				       struct drm_connector_state *conn_state)
@@ -154,6 +197,98 @@ static int intel_dp_mst_compute_config(struct intel_encoder *encoder,
 
 	intel_ddi_compute_min_voltage_level(dev_priv, pipe_config);
 
+	ret = intel_dp_mst_master_trans_compute(encoder, pipe_config,
+						conn_state);
+	if (ret)
+		return ret;
+
+	return 0;
+}
+
+static int
+intel_dp_mst_atomic_master_trans_check(struct drm_connector *connector,
+				       struct drm_atomic_state *state)
+{
+	struct drm_i915_private *dev_priv = to_i915(connector->dev);
+	struct drm_connector_state *new_conn_state, *old_conn_state;
+	struct drm_connector_list_iter conn_list_iter;
+	struct intel_crtc_state *intel_crtc_state;
+	struct intel_connector *intel_conn;
+	struct drm_crtc_state *crtc_state;
+	struct drm_connector *conn_iter;
+
+	if (INTEL_GEN(dev_priv) < 12)
+		return  0;
+
+	intel_conn = to_intel_connector(connector);
+	new_conn_state = drm_atomic_get_new_connector_state(state, connector);
+	old_conn_state = drm_atomic_get_old_connector_state(state, connector);
+
+	if (!old_conn_state->crtc && !new_conn_state->crtc)
+		return 0;
+
+	/*
+	 * 3 cases that needs be handled here:
+	 * - connector going from disabled to enabled:
+	 * nothing else need to be done, drm helpers already set mode_changed in
+	 * the CRTCs needed
+	 * - connector going from enabled to disabled:
+	 * if this transcoder was the master, all slaves needs a modeset
+	 * - connector going from enabled to enabled but it needs a modeset:
+	 * if this transcoder was the master, all slaves also needs a modeset
+	 */
+
+	/* disabled -> enabled */
+	if (!old_conn_state->crtc && new_conn_state->crtc)
+		return 0;
+
+	/* enabled -> enabled(modeset)? */
+	if (new_conn_state->crtc) {
+		crtc_state = drm_atomic_get_new_crtc_state(state,
+							   new_conn_state->crtc);
+		if (!drm_atomic_crtc_needs_modeset(crtc_state))
+			return 0;
+	}
+
+	/* handling enabled -> enabled(modeset) and enabled -> disabled */
+	crtc_state = drm_atomic_get_old_crtc_state(state, old_conn_state->crtc);
+	intel_crtc_state = to_intel_crtc_state(crtc_state);
+
+	/* If not master, nothing else needs to be handled */
+	if (!intel_dp_mst_is_master_trans(intel_crtc_state))
+		return 0;
+
+	/* It is master, add and mark all other CRTCs in the stream as changed */
+	drm_connector_list_iter_begin(state->dev, &conn_list_iter);
+	drm_for_each_connector_iter(conn_iter, &conn_list_iter) {
+		struct drm_connector_state *conn_iter_state;
+		struct intel_connector *intel_conn_iter;
+
+		intel_conn_iter = to_intel_connector(conn_iter);
+		if (intel_conn_iter->mst_port != intel_conn->mst_port)
+			continue;
+
+		conn_iter_state = drm_atomic_get_connector_state(state,
+								 conn_iter);
+		if (IS_ERR(conn_iter_state)) {
+			drm_connector_list_iter_end(&conn_list_iter);
+			return PTR_ERR(conn_iter_state);
+		}
+
+		if (!conn_iter_state->crtc)
+			continue;
+
+		crtc_state = drm_atomic_get_crtc_state(state,
+						       conn_iter_state->crtc);
+		if (IS_ERR(crtc_state)) {
+			drm_connector_list_iter_end(&conn_list_iter);
+			return PTR_ERR(conn_iter_state);
+		}
+
+		crtc_state->mode_changed = true;
+	}
+	drm_connector_list_iter_end(&conn_list_iter);
+
 	return 0;
 }
 
@@ -175,6 +310,10 @@ intel_dp_mst_atomic_check(struct drm_connector *connector,
 	if (ret)
 		return ret;
 
+	ret = intel_dp_mst_atomic_master_trans_check(connector, state);
+	if (ret)
+		return ret;
+
 	if (!old_conn_state->crtc)
 		return 0;
 
@@ -241,6 +380,9 @@ 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));
+
 	/*
 	 * From TGL spec: "If multi-stream slave transcoder: Configure
 	 * Transcoder Clock Select to direct no clock to the transcoder"
@@ -321,6 +463,9 @@ static void intel_mst_pre_enable_dp(struct intel_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);
 
 	if (first_mst_stream)
@@ -726,3 +871,21 @@ 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)
+{
+	struct drm_i915_private *dev_priv = to_i915(crtc_state->uapi.crtc->dev);
+
+	return INTEL_GEN(dev_priv) >= 12 &&
+	       intel_crtc_has_type(crtc_state, INTEL_OUTPUT_DP_MST) &&
+	       crtc_state->mst_master_transcoder == crtc_state->cpu_transcoder;
+}
+
+bool intel_dp_mst_is_slave_trans(const struct intel_crtc_state *crtc_state)
+{
+	struct drm_i915_private *dev_priv = to_i915(crtc_state->uapi.crtc->dev);
+
+	return INTEL_GEN(dev_priv) >= 12 &&
+	       intel_crtc_has_type(crtc_state, INTEL_OUTPUT_DP_MST) &&
+	       crtc_state->mst_master_transcoder != crtc_state->cpu_transcoder;
+}
diff --git a/drivers/gpu/drm/i915/display/intel_dp_mst.h b/drivers/gpu/drm/i915/display/intel_dp_mst.h
index f660ad80db04..e40767f78343 100644
--- a/drivers/gpu/drm/i915/display/intel_dp_mst.h
+++ b/drivers/gpu/drm/i915/display/intel_dp_mst.h
@@ -6,10 +6,15 @@
 #ifndef __INTEL_DP_MST_H__
 #define __INTEL_DP_MST_H__
 
+#include <stdbool.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__ */
-- 
2.24.0

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