1 files changed, 34 insertions, 0 deletions
diff --git a/drivers/gpu/drm/selftests/test-drm_dp_mst_helper.c b/drivers/gpu/drm/selftests/test-drm_dp_mst_helper.c
new file mode 100644
index 000000000000..9baa5171988d
--- /dev/null
+++ b/drivers/gpu/drm/selftests/test-drm_dp_mst_helper.c
@@ -0,0 +1,34 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Test cases for for the DRM DP MST helpers
+ */
+
+#include <drm/drm_dp_mst_helper.h>
+#include <drm/drm_print.h>
+
+#include "test-drm_modeset_common.h"
+
+int igt_dp_mst_calc_pbn_mode(void *ignored)
+{
+	int pbn, i;
+	const struct {
+		int rate;
+		int bpp;
+		int expected;
+	} test_params[] = {
+		{ 154000, 30, 689 },
+		{ 234000, 30, 1047 },
+		{ 297000, 24, 1063 },
+	};
+
+	for (i = 0; i < ARRAY_SIZE(test_params); i++) {
+		pbn = drm_dp_calc_pbn_mode(test_params[i].rate,
+					   test_params[i].bpp);
+		FAIL(pbn != test_params[i].expected,
+		     "Expected PBN %d for clock %d bpp %d, got %d\n",
+		     test_params[i].expected, test_params[i].rate,
+		     test_params[i].bpp, pbn);
+	}
+
+	return 0;
+}