[igt-dev] [v3 i-g-t 02/14] tests/kms_frontbuffer_tracking: Fix mode selection for 2x tests

[Bhanuprakash Modem]

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.

This patch will find a combination of modes that fit into the BW.

V2:
* Remove MST specific logic (Daniel)

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>
---
 tests/kms_frontbuffer_tracking.c | 33 ++++++++++++++++++++++++++++++++
 1 file changed, 33 insertions(+)

diff --git a/tests/kms_frontbuffer_tracking.c b/tests/kms_frontbuffer_tracking.c
index 2e74bec6f..84392360b 100644
--- a/tests/kms_frontbuffer_tracking.c
+++ b/tests/kms_frontbuffer_tracking.c
@@ -1683,6 +1683,33 @@ static void enable_prim_screen_and_wait(const struct test_mode *t)
 	do_assertions(ASSERT_NO_ACTION_CHANGE);
 }
 
+static void update_modeset_cached_params(void)
+{
+	bool found = false;
+
+	igt_output_set_pipe(prim_mode_params.output, prim_mode_params.pipe);
+	igt_output_set_pipe(scnd_mode_params.output, scnd_mode_params.pipe);
+
+	found = override_all_active_output_modes_to_fit_link_bw(&drm.display);
+	igt_require_f(found, "No valid mode combo found.\n");
+
+	prim_mode_params.mode_copy = *igt_output_get_mode(prim_mode_params.output);
+	prim_mode_params.mode = &prim_mode_params.mode_copy;
+	prim_mode_params.primary.w = prim_mode_params.mode->hdisplay;
+	prim_mode_params.primary.h = prim_mode_params.mode->vdisplay;
+
+	scnd_mode_params.mode_copy = *igt_output_get_mode(scnd_mode_params.output);
+	scnd_mode_params.mode = &scnd_mode_params.mode_copy;
+	scnd_mode_params.primary.w = scnd_mode_params.mode->hdisplay;
+	scnd_mode_params.primary.h = scnd_mode_params.mode->vdisplay;
+
+	fill_fb_region(&prim_mode_params.primary, COLOR_PRIM_BG);
+	fill_fb_region(&scnd_mode_params.primary, COLOR_SCND_BG);
+
+	__set_mode_for_params(&prim_mode_params);
+	__set_mode_for_params(&scnd_mode_params);
+}
+
 static void enable_both_screens_and_wait(const struct test_mode *t)
 {
 	fill_fb_region(&prim_mode_params.primary, COLOR_PRIM_BG);
@@ -1691,6 +1718,12 @@ static void enable_both_screens_and_wait(const struct test_mode *t)
 	__set_mode_for_params(&prim_mode_params);
 	__set_mode_for_params(&scnd_mode_params);
 
+	if (igt_display_try_commit_atomic(&drm.display,
+					  DRM_MODE_ATOMIC_TEST_ONLY |
+					  DRM_MODE_ATOMIC_ALLOW_MODESET,
+					  NULL) != 0)
+		update_modeset_cached_params();
+
 	igt_display_commit2(&drm.display, drm.display.is_atomic ? COMMIT_ATOMIC : COMMIT_LEGACY);
 
 	wanted_crc = &blue_crcs[t->format].crc;
-- 
2.20.1