[igt-dev] [v6 i-g-t 06/14] tests/kms_plane_scaling: Fix mode selection for 2x tests

[Bhanuprakash Modem]

This patch will find the connector/mode combination that fits
into the bandwidth when more than one monitor is connected.

Example:
  When two monitors connected through MST, the second monitor
  also tries to use the same mode. So two such modes may not
  fit into the link bandwidth. So, iterate through connected
  outputs & modes and find a combination of modes those fit
  into the link BW.

V2:
* Fix commit message (Ankit)

Cc: Imre Deak <imre.deak at intel.com>
Cc: Ankit Nautiyal <ankit.k.nautiyal at intel.com>
Cc: Daniel Vetter <daniel.vetter at ffwll.ch>
Signed-off-by: Bhanuprakash Modem <bhanuprakash.modem at intel.com>
Reviewed-by: Ankit Nautiyal <ankit.k.nautiyal at intel.com>
---
 tests/kms_plane_scaling.c | 15 ++++++++++++---
 1 file changed, 12 insertions(+), 3 deletions(-)

diff --git a/tests/kms_plane_scaling.c b/tests/kms_plane_scaling.c
index 34efc588e..7464b5bdf 100644
--- a/tests/kms_plane_scaling.c
+++ b/tests/kms_plane_scaling.c
@@ -630,9 +630,6 @@ static void test_scaler_with_multi_pipe_plane(data_t *d)
 	d->plane3 = igt_output_get_plane(output2, 0);
 	d->plane4 = get_num_scalers(d, pipe2) >= 2 ? igt_output_get_plane(output2, 1) : NULL;
 
-	mode1 = igt_output_get_mode(output1);
-	mode2 = igt_output_get_mode(output2);
-
 	igt_skip_on(!igt_display_has_format_mod(display, DRM_FORMAT_XRGB8888,
 						tiling));
 
@@ -658,8 +655,20 @@ static void test_scaler_with_multi_pipe_plane(data_t *d)
 	igt_plane_set_fb(d->plane3, &d->fb[2]);
 	if (d->plane4)
 		igt_plane_set_fb(d->plane4, &d->fb[3]);
+
+	if (igt_display_try_commit_atomic(display,
+				DRM_MODE_ATOMIC_TEST_ONLY |
+				DRM_MODE_ATOMIC_ALLOW_MODESET,
+				NULL) != 0) {
+		bool found = igt_override_all_active_output_modes_to_fit_bw(display);
+		igt_require_f(found, "No valid mode combo found.\n");
+	}
+
 	igt_display_commit2(display, COMMIT_ATOMIC);
 
+	mode1 = igt_output_get_mode(output1);
+	mode2 = igt_output_get_mode(output2);
+
 	/* Upscaling Primary */
 	igt_plane_set_size(d->plane1, mode1->hdisplay, mode1->vdisplay);
 	igt_plane_set_size(d->plane3, mode2->hdisplay, mode2->vdisplay);
-- 
2.20.1