Commit 8b076fa7 authored by Wayne Lin's avatar Wayne Lin Committed by Alex Deucher
Browse files

drm/amd/display: Add is_mst_connector debugfs entry 



[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

Tested-by: default avatarDaniel Wheeler <daniel.wheeler@amd.com>
Reviewed-by: default avatarHersen Wu <hersenxs.wu@amd.com>
Acked-by: default avatarAlan Liu <HaoPing.Liu@amd.com>
Signed-off-by: default avatarWayne Lin <Wayne.Lin@amd.com>
Signed-off-by: default avatarAlex Deucher <alexander.deucher@amd.com>
parent c8a58ce1

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

+53 −0
Original line number Diff line number Diff line
@@ -2540,6 +2540,57 @@ 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);
@@ -2549,6 +2600,7 @@ 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,
@@ -2692,6 +2744,7 @@ 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