drm/amd/display: Trigger DP2 Sequence With Uncertified Cable

DP2 sequence is triggered only if VESA certified cable is detected.

Force DP2 sequence with uncertified cable for testing purpose.
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Reviewed-by: Wenjing Liu <Wenjing.Liu@amd.com>
Acked-by: Stylon Wang <stylon.wang@amd.com>
Signed-off-by: Fangzhi Zuo <Jerry.Zuo@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

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

@@ -3431,6 +3431,30 @@ static int dp_force_sst_get(void *data, u64 *val)
 }
 DEFINE_DEBUGFS_ATTRIBUTE(dp_set_mst_en_for_sst_ops, dp_force_sst_get,
 			 dp_force_sst_set, "%llu\n");
+
+/*
+ * Force DP2 sequence without VESA certified cable.
+ * Example usage: echo 1 > /sys/kernel/debug/dri/0/amdgpu_dm_dp_ignore_cable_id
+ */
+static int dp_ignore_cable_id_set(void *data, u64 val)
+{
+	struct amdgpu_device *adev = data;
+
+	adev->dm.dc->debug.ignore_cable_id = val;
+
+	return 0;
+}
+
+static int dp_ignore_cable_id_get(void *data, u64 *val)
+{
+	struct amdgpu_device *adev = data;
+
+	*val = adev->dm.dc->debug.ignore_cable_id;
+
+	return 0;
+}
+DEFINE_DEBUGFS_ATTRIBUTE(dp_ignore_cable_id_ops, dp_ignore_cable_id_get,
+			 dp_ignore_cable_id_set, "%llu\n");
 #endif
 
 /*
@@ -3549,6 +3573,8 @@ void dtn_debugfs_init(struct amdgpu_device *adev)
 #if defined(CONFIG_DRM_AMD_DC_DCN)
 	debugfs_create_file("amdgpu_dm_dp_set_mst_en_for_sst", 0644, root, adev,
 				&dp_set_mst_en_for_sst_ops);
+	debugfs_create_file("amdgpu_dm_dp_ignore_cable_id", 0644, root, adev,
+				&dp_ignore_cable_id_ops);
 #endif
 
 	debugfs_create_file_unsafe("amdgpu_dm_visual_confirm", 0644, root, adev,