[PATCH i-g-t] tests/kms_setmode: Add HDMI 2.0 clock limit for mode selection

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

eDP modes with high clock rates were being forced on HDMI 2.0 displays,
causing kernel to reject with EINVAL. Add clock validation to skip
incompatible eDP modes and fall back to supported modes.

Signed-off-by: Jeevan B <jeevan.b@intel.com>
---
 tests/kms_setmode.c | 24 ++++++++++++++++++++++--
 1 file changed, 22 insertions(+), 2 deletions(-)

diff --git a/tests/kms_setmode.c b/tests/kms_setmode.c
index 9c0649e17..4b2f16751 100644
--- a/tests/kms_setmode.c
+++ b/tests/kms_setmode.c
@@ -79,6 +79,9 @@
 /* restricted pipe count */
 #define CRTC_RESTRICT_CNT 2
 
+/* Clock limit for HDMI 2.0 */
+#define HDMI_2_0_MAX_CLOCK_KHZ 600000
+
 static int drm_fd;
 static drmModeRes *drm_resources;
 static int filter_test_id;
@@ -270,8 +273,25 @@ static void get_mode_for_crtc(struct crtc_config *crtc,
 				if (conn->modes[j].clock < mode->clock)
 					mode = &conn->modes[j];
 			}
-			*mode_ret = *mode;
-			return;
+
+			/* Check clock limit for HDMI 2.0 */
+			bool hdmi_compatible = true;
+
+			for (int k = 0; k < crtc->connector_count; k++) {
+				drmModeConnector *other_conn = crtc->cconfs[k].connector;
+
+				if ((other_conn->connector_type == DRM_MODE_CONNECTOR_HDMIA ||
+				    other_conn->connector_type == DRM_MODE_CONNECTOR_HDMIB) &&
+				    mode->clock > HDMI_2_0_MAX_CLOCK_KHZ) {
+					hdmi_compatible = false;
+					break;
+				}
+			}
+
+			if (hdmi_compatible && crtc_supports_mode(crtc, mode)) {
+				*mode_ret = *mode;
+				return;
+			}
 		}
 	}
 
-- 
2.43.0