From: Wayne Lin <Wayne.Lin@xxxxxxx>
[Why & How]
Add "is_mst_connector" debugfs entry to help distinguish whether
a connector is in a mst topology or not.
Access it with the following command:
cat /sys/kernel/debug/dri/0/DP-X/is_mst_connector
Result:
- "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
Reviewed-by: Hersen Wu <hersenxs.wu@xxxxxxx>
Acked-by: Alan Liu <HaoPing.Liu@xxxxxxx>
Signed-off-by: Wayne Lin <Wayne.Lin@xxxxxxx>
---
.../amd/display/amdgpu_dm/amdgpu_dm_debugfs.c | 53 +++++++++++++++++++
1 file changed, 53 insertions(+)
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 b764198eca5c..991e58a3a78c 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
@@ -2557,6 +2557,57 @@ 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;
+}
+
+
DEFINE_SHOW_ATTRIBUTE(dp_dsc_fec_support);
DEFINE_SHOW_ATTRIBUTE(dmub_fw_state);
DEFINE_SHOW_ATTRIBUTE(dmub_tracebuffer);
@@ -2567,6 +2618,7 @@ DEFINE_SHOW_ATTRIBUTE(hdcp_sink_capability);
#endif
DEFINE_SHOW_ATTRIBUTE(internal_display);
DEFINE_SHOW_ATTRIBUTE(psr_capability);
+DEFINE_SHOW_ATTRIBUTE(dp_is_mst_connector);
static const struct file_operations dp_dsc_clock_en_debugfs_fops = {
.owner = THIS_MODULE,
@@ -2710,6 +2762,7 @@ 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}
};
#ifdef CONFIG_DRM_AMD_DC_HDCP
--
2.37.0
