[igt-dev] [i-g-t V2] tests/kms_dither: Set max_bpc before exiting the subtest

[Bhanuprakash Modem]

Before exiting the subtest, we must reset the connector's "max_bpc"
property to it's default value, else it may effect the consequent
subtests.

V2:
* Don't trigger a subtest if requested bpc > connecot's max_bpc.

Signed-off-by: Bhanuprakash Modem <bhanuprakash.modem at intel.com>
---
 tests/kms_dither.c | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)

diff --git a/tests/kms_dither.c b/tests/kms_dither.c
index 02896b37..ace89062 100644
--- a/tests/kms_dither.c
+++ b/tests/kms_dither.c
@@ -128,6 +128,7 @@ static void test_dithering(data_t *data, enum pipe pipe,
 	igt_display_t *display = &data->display;
 	dither_status_t status;
 	int bpc, ret;
+	bool constraint;
 
 	igt_info("Dithering test execution on %s PIPE_%s\n",
 			output->name, kmstest_pipe_name(pipe));
@@ -148,6 +149,13 @@ static void test_dithering(data_t *data, enum pipe pipe,
 	else
 		ret = igt_display_try_commit2(display, COMMIT_LEGACY);
 
+	if (ret)
+		goto cleanup;
+
+	constraint = i915_clock_constraint(data, pipe, output, output_bpc);
+	if (!constraint)
+		goto cleanup;
+
 	igt_require_f(!ret, "%s don't support %d-bpc\n",
 				output->name, output_bpc);
 
@@ -174,12 +182,17 @@ static void test_dithering(data_t *data, enum pipe pipe,
 	* Otherwise, previously updated value will stay forever and
 	* may cause the failures for next/other subtests.
 	*/
+cleanup:
 	igt_output_set_prop_value(output, IGT_CONNECTOR_MAX_BPC, bpc);
 	igt_plane_set_fb(data->primary, NULL);
 	igt_output_set_pipe(output, PIPE_NONE);
 	igt_display_commit2(display, display->is_atomic ? COMMIT_ATOMIC : COMMIT_LEGACY);
 	igt_remove_fb(data->drm_fd, &data->fb);
 
+	igt_require_f(!ret, "%s don't support %d-bpc\n", output->name, output_bpc);
+	igt_require_f(constraint, "No supported mode found to use %d-bpc on %s\n",
+				  output_bpc, output->name);
+
 	/* Compute the result. */
 	if (fb_bpc > output_bpc)
 		igt_assert_f(status.dither, "(fb_%dbpc > output_%dbpc): Dither should be enabled\n",
@@ -210,6 +223,9 @@ run_dither_test(data_t *data, int fb_bpc, int fb_format, int output_bpc)
 		if (!is_supported(output))
 			continue;
 
+		if (igt_get_output_max_bpc(data->drm_fd, output->name) < output_bpc)
+			continue;
+
 		for_each_pipe(display, pipe) {
 			if (igt_pipe_connector_valid(pipe, output)) {
 				igt_dynamic_f("pipe-%s-%s",
-- 
2.35.1