[PATCH i-g-t 2/2] tests/kms_setmode: Fix clone mode mismatch by preferring eDP mode

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

If an eDP connector is present, prefer selecting its lowest clock mode for
cloning. Some eDP panels support only high refresh rate (HRR) modes,
which may not match modes supported by external displays. To avoid invalid
clone configurations and test failures, we choose the lowest clock mode
from the eDP connector when available.

v2: Fix logic for eDP fallback.
v3: Fix comment to say ‘lowest clock mode selected’ instead of
    ‘default mode’.
v4: Update commit message.

Signed-off-by: Jeevan B <jeevan.b@intel.com>
---
 tests/kms_setmode.c | 19 +++++++++++++++++++
 1 file changed, 19 insertions(+)

diff --git a/tests/kms_setmode.c b/tests/kms_setmode.c
index 48d0c3e1e..135918007 100644
--- a/tests/kms_setmode.c
+++ b/tests/kms_setmode.c
@@ -256,6 +256,25 @@ static void get_mode_for_crtc(struct crtc_config *crtc,
 		}
 	}
 
+	/* If an eDP connector is present, iterate through its modes and
+	 * pick a mode with lowest clock, since internal panels typically
+	 * dictate the clone mode and may have HRR support, making them
+	 * incompatible with modes supported by external displays.
+	 */
+	for (i = 0; i < crtc->connector_count; i++) {
+		drmModeConnector *conn = crtc->cconfs[i].connector;
+
+		if (conn->connector_type == DRM_MODE_CONNECTOR_eDP) {
+			mode = &conn->modes[0];
+			for (int j = 1; j < conn->count_modes; j++) {
+				if (conn->modes[j].clock < mode->clock)
+					mode = &conn->modes[j];
+			}
+			*mode_ret = *mode;
+			return;
+		}
+	}
+
 	/*
 	 * If none is found then just pick the default mode from all connectors
 	 * with the smallest clock, hope the other connectors can support it by
-- 
2.43.0