drm/amd/display: Add tags for indicating mst progress status

[Why & How]
In order to leverage igt tool to maintain mst feature, expose new
debugfs entry "mst_progress_status".

In our dm flow, record down the result of each phase of mst and user
can examine the mst result by checking whether each phase get completed
successfully.
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Reviewed-by: Hersen Wu <hersenxs.wu@amd.com>
Acked-by: Alan Liu <HaoPing.Liu@amd.com>
Signed-off-by: Wayne Lin <Wayne.Lin@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.h

@@ -571,6 +571,14 @@ struct dsc_preferred_settings {
 	bool dsc_force_disable_passthrough;
 };
 
+enum mst_progress_status {
+	MST_STATUS_DEFAULT = 0,
+	MST_PROBE = BIT(0),
+	MST_REMOTE_EDID = BIT(1),
+	MST_ALLOCATE_NEW_PAYLOAD = BIT(2),
+	MST_CLEAR_ALLOCATED_PAYLOAD = BIT(3),
+};
+
 struct amdgpu_dm_connector {
 
 	struct drm_connector base;
@@ -623,8 +631,20 @@ struct amdgpu_dm_connector {
 	struct drm_display_mode freesync_vid_base;
 
 	int psr_skip_count;
+
+	/* Record progress status of mst*/
+	uint8_t mst_status;
 };
 
+static inline void amdgpu_dm_set_mst_status(uint8_t *status,
+		uint8_t flags, bool set)
+{
+	if (set)
+		*status |= flags;
+	else
+		*status &= ~flags;
+}
+
 #define to_amdgpu_dm_connector(x) container_of(x, struct amdgpu_dm_connector, base)
 
 extern const struct amdgpu_ip_block_version dm_ip_block;

drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_debugfs.c

@@ -50,6 +50,13 @@ struct dmub_debugfs_trace_entry {
 	uint32_t param1;
 };
 
+static const char *const mst_progress_status[] = {
+	"probe",
+	"remote_edid",
+	"allocate_new_payload",
+	"clear_allocated_payload",
+};
+
 /* parse_write_buffer_into_params - Helper function to parse debugfs write buffer into an array
  *
  * Function takes in attributes passed to debugfs write entry
@@ -2590,6 +2597,41 @@ static int dp_is_mst_connector_show(struct seq_file *m, void *unused)
 	return 0;
 }
 
+/*
+ * function description: Read out the mst progress status
+ *
+ * This function helps to determine the mst progress status of
+ * a mst connector.
+ *
+ * Access it with the following command:
+ *
+ *	cat /sys/kernel/debug/dri/0/DP-X/mst_progress_status
+ *
+ */
+static int dp_mst_progress_status_show(struct seq_file *m, void *unused)
+{
+	struct drm_connector *connector = m->private;
+	struct amdgpu_dm_connector *aconnector = to_amdgpu_dm_connector(connector);
+	struct amdgpu_device *adev = drm_to_adev(connector->dev);
+	int i;
+
+	mutex_lock(&aconnector->hpd_lock);
+	mutex_lock(&adev->dm.dc_lock);
+
+	if (aconnector->mst_status == MST_STATUS_DEFAULT) {
+		seq_puts(m, "disabled\n");
+	} else {
+		for (i = 0; i < sizeof(mst_progress_status)/sizeof(char *); i++)
+			seq_printf(m, "%s:%s\n",
+				mst_progress_status[i],
+				aconnector->mst_status & BIT(i) ? "done" : "not_done");
+	}
+
+	mutex_unlock(&adev->dm.dc_lock);
+	mutex_unlock(&aconnector->hpd_lock);
+
+	return 0;
+}
 
 DEFINE_SHOW_ATTRIBUTE(dp_dsc_fec_support);
 DEFINE_SHOW_ATTRIBUTE(dmub_fw_state);
@@ -2601,6 +2643,7 @@ DEFINE_SHOW_ATTRIBUTE(hdcp_sink_capability);
 DEFINE_SHOW_ATTRIBUTE(internal_display);
 DEFINE_SHOW_ATTRIBUTE(psr_capability);
 DEFINE_SHOW_ATTRIBUTE(dp_is_mst_connector);
+DEFINE_SHOW_ATTRIBUTE(dp_mst_progress_status);
 
 static const struct file_operations dp_dsc_clock_en_debugfs_fops = {
 	.owner = THIS_MODULE,
@@ -2744,7 +2787,8 @@ static const struct {
 		{"dp_dsc_fec_support", &dp_dsc_fec_support_fops},
 		{"max_bpc", &dp_max_bpc_debugfs_fops},
 		{"dsc_disable_passthrough", &dp_dsc_disable_passthrough_debugfs_fops},
-		{"is_mst_connector", &dp_is_mst_connector_fops}
+		{"is_mst_connector", &dp_is_mst_connector_fops},
+		{"mst_progress_status", &dp_mst_progress_status_fops}
 };
 
 #ifdef CONFIG_DRM_AMD_DC_HDCP

drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_helpers.c

@@ -312,6 +312,8 @@ bool dm_helpers_dp_mst_send_payload_allocation(
 	struct amdgpu_dm_connector *aconnector;
 	struct drm_dp_mst_topology_mgr *mst_mgr;
 	struct drm_dp_mst_port *mst_port;
+	enum mst_progress_status set_flag = MST_ALLOCATE_NEW_PAYLOAD;
+	enum mst_progress_status clr_flag = MST_CLEAR_ALLOCATED_PAYLOAD;
 
 	aconnector = (struct amdgpu_dm_connector *)stream->dm_stream_context;
 
@@ -325,8 +327,20 @@ bool dm_helpers_dp_mst_send_payload_allocation(
 	if (!mst_mgr->mst_state)
 		return false;
 
-	/* It's OK for this to fail */
-	drm_dp_update_payload_part2(mst_mgr);
+	if (!enable) {
+		set_flag = MST_CLEAR_ALLOCATED_PAYLOAD;
+		clr_flag = MST_ALLOCATE_NEW_PAYLOAD;
+	}
+
+	if (drm_dp_update_payload_part2(mst_mgr)) {
+		amdgpu_dm_set_mst_status(&aconnector->mst_status,
+			set_flag, false);
+	} else {
+		amdgpu_dm_set_mst_status(&aconnector->mst_status,
+			set_flag, true);
+		amdgpu_dm_set_mst_status(&aconnector->mst_status,
+			clr_flag, false);
+	}
 
 	if (!enable)
 		drm_dp_mst_deallocate_vcpi(mst_mgr, mst_port);

drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_mst_types.c

@@ -179,6 +179,8 @@ amdgpu_dm_mst_connector_early_unregister(struct drm_connector *connector)
 		aconnector->dc_sink = NULL;
 		aconnector->edid = NULL;
 	}
+
+	aconnector->mst_status = MST_STATUS_DEFAULT;
 	drm_modeset_unlock(&root->mst_mgr.base.lock);
 }
 
@@ -279,6 +281,9 @@ static int dm_dp_mst_get_modes(struct drm_connector *connector)
 		edid = drm_dp_mst_get_edid(connector, &aconnector->mst_port->mst_mgr, aconnector->port);
 
 		if (!edid) {
+			amdgpu_dm_set_mst_status(&aconnector->mst_status,
+			MST_REMOTE_EDID, false);
+
 			drm_connector_update_edid_property(
 				&aconnector->base,
 				NULL);
@@ -309,6 +314,8 @@ static int dm_dp_mst_get_modes(struct drm_connector *connector)
 		}
 
 		aconnector->edid = edid;
+		amdgpu_dm_set_mst_status(&aconnector->mst_status,
+			MST_REMOTE_EDID, true);
 	}
 
 	if (aconnector->dc_sink && aconnector->dc_sink->sink_signal == SIGNAL_TYPE_VIRTUAL) {
@@ -430,6 +437,10 @@ dm_dp_mst_detect(struct drm_connector *connector,
 		dc_sink_release(aconnector->dc_sink);
 		aconnector->dc_sink = NULL;
 		aconnector->edid = NULL;
+
+		amdgpu_dm_set_mst_status(&aconnector->mst_status,
+			MST_REMOTE_EDID | MST_ALLOCATE_NEW_PAYLOAD | MST_CLEAR_ALLOCATED_PAYLOAD,
+			false);
 	}
 
 	return connection_status;
@@ -526,6 +537,8 @@ dm_dp_add_mst_connector(struct drm_dp_mst_topology_mgr *mgr,
 	connector = &aconnector->base;
 	aconnector->port = port;
 	aconnector->mst_port = master;
+	amdgpu_dm_set_mst_status(&aconnector->mst_status,
+			MST_PROBE, true);
 
 	if (drm_connector_init(
 		dev,