[PATCH i-g-t v2] 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.

v2: Add HDMI 2.0 clock limit helper, drop crtc_supports_mode(),
    and ensure per-connector compatibility to avoid invalid modes.

Signed-off-by: Jeevan B <jeevan.b@intel.com>
---
 tests/kms_setmode.c | 44 ++++++++++++++++++++++++++++++++++++++++++--
 1 file changed, 42 insertions(+), 2 deletions(-)

diff --git a/tests/kms_setmode.c b/tests/kms_setmode.c
index 1f2849bc2..f1c1afe45 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;
@@ -165,6 +168,16 @@ static bool connector_supports_mode(drmModeConnector *connector,
 	return false;
 }
 
+static bool hdmi_connector_mode_exceeds_hdmi20_limit(drmModeConnector *connector,
+						     drmModeModeInfo *mode)
+{
+	if (connector->connector_type != DRM_MODE_CONNECTOR_HDMIA &&
+	    connector->connector_type != DRM_MODE_CONNECTOR_HDMIB)
+		return false;
+
+	return mode->clock > HDMI_2_0_MAX_CLOCK_KHZ;
+}
+
 static bool crtc_supports_mode(struct crtc_config *crtc, drmModeModeInfo *mode)
 {
 	int i;
@@ -270,8 +283,35 @@ 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 HDMI 2.0 clock + per-connector compatibility */
+			{
+				int k;
+				bool compatible = true;
+
+				for (k = 0; k < crtc->connector_count; k++) {
+					drmModeConnector *other_conn =
+						crtc->cconfs[k].connector;
+
+					/* HDMI 2.0 clock constraint */
+					if (hdmi_connector_mode_exceeds_hdmi20_limit(other_conn,
+										     mode)) {
+						compatible = false;
+						break;
+					}
+
+					/* Ensure connector supports the mode */
+					if (!connector_supports_mode(other_conn, mode)) {
+						compatible = false;
+						break;
+					}
+				}
+
+				if (compatible) {
+					*mode_ret = *mode;
+					return;
+				}
+			}
 		}
 	}
 
-- 
2.43.0