1 files changed, 111 insertions, 3 deletions

diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_debugfs.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_debugfs.c
index a1f40d0cd41c..aa4edf182095 100644
--- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_debugfs.c
+++ b/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
@@ -1256,14 +1263,22 @@ static ssize_t trigger_hotplug(struct file *f, const char __user *buf,
 		return -EINVAL;
 	}
 
+	kfree(wr_buf);
+
 	if (param_nums <= 0) {
 		DRM_DEBUG_DRIVER("user data not be read\n");
-		kfree(wr_buf);
+		return -EINVAL;
+	}
+
+	mutex_lock(&aconnector->hpd_lock);
+
+	/* Don't support for mst end device*/
+	if (aconnector->mst_port) {
+		mutex_unlock(&aconnector->hpd_lock);
 		return -EINVAL;
 	}
 
 	if (param[0] == 1) {
-		mutex_lock(&aconnector->hpd_lock);
 
 		if (!dc_link_detect_sink(aconnector->dc_link, &new_connection_type) &&
 			new_connection_type != dc_connection_none)
@@ -1300,6 +1315,10 @@ static ssize_t trigger_hotplug(struct file *f, const char __user *buf,
 
 		amdgpu_dm_update_connector_after_detect(aconnector);
 
+		/* If the aconnector is the root node in mst topology */
+		if (aconnector->mst_mgr.mst_state == true)
+			reset_cur_dp_mst_topology(link);
+
 		drm_modeset_lock_all(dev);
 		dm_restore_drm_connector_state(dev, connector);
 		drm_modeset_unlock_all(dev);
@@ -1310,7 +1329,6 @@ static ssize_t trigger_hotplug(struct file *f, const char __user *buf,
 unlock:
 	mutex_unlock(&aconnector->hpd_lock);
 
-	kfree(wr_buf);
 	return size;
 }
 
@@ -2529,6 +2547,92 @@ static int target_backlight_show(struct seq_file *m, void *unused)
 	return 0;
 }
 
+/*
+ * function description: Determine if the connector is mst connector
+ *
+ * This function helps to determine whether a connector is a mst connector.
+ * - "root" stands for the root connector of the topology
+ * - "branch" stands for branch device of the topology
+ * - "end" stands for leaf node connector of the topology
+ * - "no" stands for the connector is not a device of a mst topology
+ * Access it with the following command:
+ *
+ *	cat /sys/kernel/debug/dri/0/DP-X/is_mst_connector
+ *
+ */
+static int dp_is_mst_connector_show(struct seq_file *m, void *unused)
+{
+	struct drm_connector *connector = m->private;
+	struct amdgpu_dm_connector *aconnector = to_amdgpu_dm_connector(connector);
+	struct drm_dp_mst_topology_mgr *mgr = NULL;
+	struct drm_dp_mst_port *port = NULL;
+	char *role = NULL;
+
+	mutex_lock(&aconnector->hpd_lock);
+
+	if (aconnector->mst_mgr.mst_state) {
+		role = "root";
+	} else if (aconnector->mst_port &&
+		aconnector->mst_port->mst_mgr.mst_state) {
+
+		role = "end";
+
+		mgr = &aconnector->mst_port->mst_mgr;
+		port = aconnector->port;
+
+		drm_modeset_lock(&mgr->base.lock, NULL);
+		if (port->pdt == DP_PEER_DEVICE_MST_BRANCHING &&
+			port->mcs)
+			role = "branch";
+		drm_modeset_unlock(&mgr->base.lock);
+
+	} else {
+		role = "no";
+	}
+
+	seq_printf(m, "%s\n", role);
+
+	mutex_unlock(&aconnector->hpd_lock);
+
+	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);
 DEFINE_SHOW_ATTRIBUTE(dmub_tracebuffer);
@@ -2538,6 +2642,8 @@ DEFINE_SHOW_ATTRIBUTE(hdcp_sink_capability);
 #endif
 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,
@@ -2681,6 +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},
+		{"mst_progress_status", &dp_mst_progress_status_fops}
 };
 
 #ifdef CONFIG_DRM_AMD_DC_HDCP