[Intel-gfx] [PATCH] drm/i915/hdmi: enable resolution 3840x2160 for type 1 HDMI

[Jian-Hong Pan]

Type 1 HDMI may be version 1.3 or upper, which supports higher max TMDS
clock for higher resolutions, like 3840x2160. This patch sets max TMDS
clock according to the chip, if the adapter is type 1 HDMI.

Buglink: https://bugs.freedesktop.org/show_bug.cgi?id=112018
Fixes: b1ba124d8e95 ("drm/i915: Respect DP++ adaptor TMDS clock limit")
Signed-off-by: Jian-Hong Pan <jian-hong at endlessm.com>
---
 drivers/gpu/drm/i915/display/intel_hdmi.c | 13 +++++++++++--
 1 file changed, 11 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/i915/display/intel_hdmi.c b/drivers/gpu/drm/i915/display/intel_hdmi.c
index e02f0faecf02..74e4426ffcad 100644
--- a/drivers/gpu/drm/i915/display/intel_hdmi.c
+++ b/drivers/gpu/drm/i915/display/intel_hdmi.c
@@ -2454,6 +2454,7 @@ intel_hdmi_dp_dual_mode_detect(struct drm_connector *connector, bool has_edid)
 {
 	struct drm_i915_private *dev_priv = to_i915(connector->dev);
 	struct intel_hdmi *hdmi = intel_attached_hdmi(connector);
+	struct intel_encoder *encoder = &hdmi_to_dig_port(hdmi)->base;
 	enum port port = hdmi_to_dig_port(hdmi)->base.port;
 	struct i2c_adapter *adapter =
 		intel_gmbus_get_adapter(dev_priv, hdmi->ddc_bus);
@@ -2488,8 +2489,16 @@ intel_hdmi_dp_dual_mode_detect(struct drm_connector *connector, bool has_edid)
 		return;
 
 	hdmi->dp_dual_mode.type = type;
-	hdmi->dp_dual_mode.max_tmds_clock =
-		drm_dp_dual_mode_max_tmds_clock(type, adapter);
+	/* Type 1 HDMI may be version 1.3 or upper, which supports higher max
+	 * TMDS clock for higher resolutions, like 3840x2160. So, set it
+	 * according to the chip, if the adapter is type 1 HDMI.
+	 */
+	if (type == DRM_DP_DUAL_MODE_TYPE1_HDMI)
+		hdmi->dp_dual_mode.max_tmds_clock =
+			intel_hdmi_source_max_tmds_clock(encoder);
+	else
+		hdmi->dp_dual_mode.max_tmds_clock =
+			drm_dp_dual_mode_max_tmds_clock(type, adapter);
 
 	DRM_DEBUG_KMS("DP dual mode adaptor (%s) detected (max TMDS clock: %d kHz)\n",
 		      drm_dp_get_dual_mode_type_name(type),
-- 
2.23.0