[igt-dev] [PATCH i-g-t v3] tests/kms_concurrent: Move bandwidth calculation to igt_fixture

[Mika Kahola]

The commit 153b34b5353df8c18a87d ("tests/kms_concurrent:
Test maximum number of planes supported by the platform")
caused regression on HSW pipe B testing such as.

IGT-Version: 1.25-gfd8248084 (x86_64) (Linux: 5.6.0-rc7-CI-CI_DRM_8194+ x86_64)
Starting subtest: pipe-B
Testing resolution with connector VGA-1 using pipe B with seed 1585245074
child 0 died with signal 11, Segmentation fault
Subtest pipe-B: FAIL (0.330s)

To fix this, we need move bandwidth calculation routines into part of
igt_fixture instead of calculating it just before actual testing. The patch
takes the minimum of those maximum number of planes for given output.

v2: Limit bandwidth check only gen11+ (CI)
v3: Loop child process 5x longer when running test with 1 iteration (CI)

Signed-off-by: Mika Kahola <mika.kahola at intel.com>
---
 tests/kms_concurrent.c | 30 ++++++++++++++++--------------
 1 file changed, 16 insertions(+), 14 deletions(-)

diff --git a/tests/kms_concurrent.c b/tests/kms_concurrent.c
index 1403e990..31c5620a 100644
--- a/tests/kms_concurrent.c
+++ b/tests/kms_concurrent.c
@@ -36,6 +36,7 @@ typedef struct {
 	igt_display_t display;
 	igt_plane_t **plane;
 	struct igt_fb *fb;
+	int max_planes;
 } data_t;
 
 /* Command line parameters. */
@@ -223,13 +224,13 @@ test_plane_position_with_output(data_t *data, enum pipe pipe, int max_planes,
 				igt_output_t *output)
 {
 	int i;
-	int iterations = opt.iterations < 1 ? 1 : opt.iterations;
+	int iterations = opt.iterations < 5 ? 1 : opt.iterations;
 	bool loop_forever = opt.iterations == LOOP_FOREVER ? true : false;
 
 	igt_pipe_refresh(&data->display, pipe, true);
 
 	i = 0;
-	while (i < iterations || loop_forever) {
+	while (i < iterations + 1 || loop_forever) {
 		prepare_planes(data, pipe, max_planes, output);
 		igt_display_commit2(&data->display, COMMIT_ATOMIC);
 
@@ -321,30 +322,30 @@ static void
 run_tests_for_pipe(data_t *data, enum pipe pipe)
 {
 	igt_output_t *output;
-	int max_planes;
 
 	igt_fixture {
 		int valid_tests = 0;
+		int n_planes = data->display.pipes[pipe].n_planes;
 
 		igt_skip_on(pipe >= data->display.n_pipes);
-		igt_require(data->display.pipes[pipe].n_planes > 0);
+		igt_require(n_planes > 0);
 
-		for_each_valid_output_on_pipe(&data->display, pipe, output)
+		for_each_valid_output_on_pipe(&data->display, pipe, output) {
+			if (intel_gen(intel_get_drm_devid(data->drm_fd)) >= 11) {
+				test_init(data, pipe, n_planes, output);
+				data->max_planes = min(data->max_planes,
+							test_bandwidth(data, pipe, output));
+				test_fini(data, pipe, n_planes, output);
+			}
 			valid_tests++;
-
+		}
 		igt_require_f(valid_tests, "no valid crtc/connector combinations found\n");
+		igt_display_reset(&data->display);
 	}
 
 	igt_subtest_f("pipe-%s", kmstest_pipe_name(pipe)) {
 		for_each_valid_output_on_pipe(&data->display, pipe, output) {
-			int n_planes = data->display.pipes[pipe].n_planes;
-
-			test_init(data, pipe, n_planes, output);
-			max_planes = test_bandwidth(data, pipe, output);
-			test_fini(data, pipe, n_planes, output);
-
-			igt_display_reset(&data->display);
-			run_test(data, pipe, max_planes, output);
+			run_test(data, pipe, data->max_planes, output);
 		}
 	}
 }
@@ -392,6 +393,7 @@ igt_main_args("", long_options, help_str, opt_handler, NULL)
 		kmstest_set_vt_graphics_mode();
 		igt_display_require(&data.display, data.drm_fd);
 		igt_require(data.display.is_atomic);
+		data.max_planes = data.display.pipes[0].n_planes;
 	}
 
 	for_each_pipe_static(pipe) {
-- 
2.20.1