[Intel-gfx] [PATCH v2] drm/i915/hdmi: Prune modes that require HDMI2.1 FRL

[Ankit Nautiyal]

HDMI2.1 requires some higher resolution video modes to be enumerated
only if HDMI2.1 Fixed Rate Link (FRL) is supported.
Current platforms do not support FRL transmission so prune modes that
require HDMI2.1 FRL.

v2: Fixed the condition to check for dotclock > 600.
Return MODE_CLOCK_HIGH as mode status.

Signed-off-by: Ankit Nautiyal <ankit.k.nautiyal at intel.com>
Reviewed-by: Arun R Murthy <arun.r.murthy at intel.com> (v1)
---
 drivers/gpu/drm/i915/display/intel_hdmi.c | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/drivers/gpu/drm/i915/display/intel_hdmi.c b/drivers/gpu/drm/i915/display/intel_hdmi.c
index ebd91aa69dd2..a88f589351fa 100644
--- a/drivers/gpu/drm/i915/display/intel_hdmi.c
+++ b/drivers/gpu/drm/i915/display/intel_hdmi.c
@@ -2001,6 +2001,15 @@ intel_hdmi_mode_valid(struct drm_connector *connector,
 		clock *= 2;
 	}
 
+	/*
+	 * HDMI2.1 requires higher resolution modes like 8k60, 4K120 to be
+	 * enumerated only if FRL is supported. Current platforms do not support
+	 * FRL so prune the higher resolution modes that require doctclock more
+	 * than 600MHz.
+	 */
+	if (clock > 600000)
+		return MODE_CLOCK_HIGH;
+
 	ycbcr_420_only = drm_mode_is_420_only(&connector->display_info, mode);
 
 	status = intel_hdmi_mode_clock_valid(connector, clock, has_hdmi_sink, ycbcr_420_only);
-- 
2.25.1