[PATCH i-g-t] tests/kms_display_modes: Skip mirrored pipe combinations

[Jeevan B <jeevan.b@intel.com>]

Use a canonical pipe ordering in extended-mode-basic so each pipe pair
is tested only once. This removes mirrored combinations (A-B and B-A)
that provide duplicate coverage.

Reducing these redundant combinations lowers the total number of dynamic
subtests, helping prevent incomplete test execution in CI while
preserving coverage of all pipe and output pairings.

v2: Skip mirrored pipe pairs, but keep both directions for SST<->MST
    combos.

Signed-off-by: Jeevan B <jeevan.b@intel.com>
---
 tests/kms_display_modes.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/tests/kms_display_modes.c b/tests/kms_display_modes.c
index d8aae4256..c1876aa05 100644
--- a/tests/kms_display_modes.c
+++ b/tests/kms_display_modes.c
@@ -193,6 +193,11 @@ static void run_extendedmode_test(data_t *data) {
 			if (output1 == output2)
 				continue;
 
+			if (crtc1->pipe > crtc2->pipe &&
+			    igt_check_output_is_dp_mst(output1) ==
+			    igt_check_output_is_dp_mst(output2))
+				continue;
+
 			igt_display_reset(display);
 
 			igt_output_set_crtc(output1, crtc1);
-- 
2.43.0