[PATCH] drm/edid: temporary workaround to pass HDMI 2.0 compliance HF1-13

Lee Shawn C shawn.c.lee at intel.com
Mon Feb 17 17:41:39 UTC 2020


Test case HF1-13 for HDMI 2.0 compliance would ask DUT to downgrade
output resolution to 720x480 or 720x576 (lower than 3.4Gbps).
And check scrambling feature was disabled as well.

But QD980 report it can support low rate scrambling. The vendor
specific data block byte[6] was 0x88. If driver enabled scrambling
rely on this info. Then HF1-13 would not get pass because DUT have
to disable scrambling to run this case.

Cc: Jani Nikula <jani.nikula at intel.com>
Cc: Ville Syrjälä <ville.syrjala at linux.intel.com>
Cc: Clint Taylor <clinton.a.taylor at intel.com>
Cc: Cooper Chiou <cooper.chiou at intel.com>
Signed-off-by: Lee Shawn C <shawn.c.lee at intel.com>
---
 drivers/gpu/drm/drm_edid.c | 13 ++++++++++---
 1 file changed, 10 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c
index 99769d6c9f84..0b4badc20c35 100644
--- a/drivers/gpu/drm/drm_edid.c
+++ b/drivers/gpu/drm/drm_edid.c
@@ -85,6 +85,8 @@
 #define EDID_QUIRK_FORCE_10BPC			(1 << 11)
 /* Non desktop display (i.e. HMD) */
 #define EDID_QUIRK_NON_DESKTOP			(1 << 12)
+/* Do not enable low rates scrambling */
+#define EDID_QUIRK_DISABLE_LOW_RATE_SCRAMBLING	(1 << 13)
 
 struct detailed_mode_closure {
 	struct drm_connector *connector;
@@ -214,6 +216,9 @@ static const struct edid_quirk {
 
 	/* OSVR HDK and HDK2 VR Headsets */
 	{ "SVR", 0x1019, EDID_QUIRK_NON_DESKTOP },
+
+	/* Quantumdata 980 test platform */
+	{ "QDI", 0x03D4, EDID_QUIRK_DISABLE_LOW_RATE_SCRAMBLING },
 };
 
 /*
@@ -4710,10 +4715,11 @@ static void drm_parse_ycbcr420_deep_color_info(struct drm_connector *connector,
 }
 
 static void drm_parse_hdmi_forum_vsdb(struct drm_connector *connector,
-				 const u8 *hf_vsdb)
+				 const u8 *hf_vsdb, const struct edid *edid)
 {
 	struct drm_display_info *display = &connector->display_info;
 	struct drm_hdmi_info *hdmi = &display->hdmi;
+	u32 quirks = edid_get_quirks(edid);
 
 	display->has_hdmi_infoframe = true;
 
@@ -4747,7 +4753,8 @@ static void drm_parse_hdmi_forum_vsdb(struct drm_connector *connector,
 			scdc->scrambling.supported = true;
 
 			/* Few sinks support scrambling for clocks < 340M */
-			if ((hf_vsdb[6] & 0x8))
+			if ((hf_vsdb[6] & 0x8) &&
+			    !(quirks & EDID_QUIRK_DISABLE_LOW_RATE_SCRAMBLING))
 				scdc->scrambling.low_rates = true;
 		}
 	}
@@ -4870,7 +4877,7 @@ static void drm_parse_cea_ext(struct drm_connector *connector,
 		if (cea_db_is_hdmi_vsdb(db))
 			drm_parse_hdmi_vsdb_video(connector, db);
 		if (cea_db_is_hdmi_forum_vsdb(db))
-			drm_parse_hdmi_forum_vsdb(connector, db);
+			drm_parse_hdmi_forum_vsdb(connector, db, edid);
 		if (cea_db_is_y420cmdb(db))
 			drm_parse_y420cmdb_bitmap(connector, db);
 		if (cea_db_is_vcdb(db))
-- 
2.17.1



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