[PATCH 1/9] drm/drm_edid: Avoid HDMI2.1 VICs in AVI Infoframe for older HDMI sinks

[Ankit Nautiyal]

Modify the check for CEA modes, to avoid writing VICs added in
CTA-861-G (meant for HDMI2.1) in AVI infoframes for older HDMI sinks.

This patch also adds a function to determine if sink is HDMI2.1
and uses corrects the drm message to show HDMI2.1 sink detetction.

Signed-off-by: Ankit Nautiyal <ankit.k.nautiyal at intel.com>
---
 drivers/gpu/drm/drm_edid.c | 24 +++++++++++++++++++++++-
 1 file changed, 23 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c
index 47465b9765f1..d3b9f9fb6c6b 100644
--- a/drivers/gpu/drm/drm_edid.c
+++ b/drivers/gpu/drm/drm_edid.c
@@ -6758,6 +6758,18 @@ void drm_set_preferred_mode(struct drm_connector *connector,
 }
 EXPORT_SYMBOL(drm_set_preferred_mode);
 
+static bool is_hdmi21_sink(const struct drm_connector *connector)
+{
+	/*
+	 * FIXME: sil-sii8620 doesn't have a connector around when
+	 * we need one, so we have to be prepared for a NULL connector.
+	 */
+	if (!connector)
+		return true;
+
+	return connector->display_info.hdmi.max_frl_rate_per_lane ? true : false;
+}
+
 static bool is_hdmi2_sink(const struct drm_connector *connector)
 {
 	/*
@@ -6807,8 +6819,18 @@ static u8 drm_mode_cea_vic(const struct drm_connector *connector,
 	 * HDMI 1.4 VIC range: 1 <= VIC <= 64 (CEA-861-D) but
 	 * HDMI 2.0 VIC range: 1 <= VIC <= 107 (CEA-861-F). So we
 	 * have to make sure we dont break HDMI 1.4 sinks.
+	 * Similarly,
+	 * HDMI 2.1 VIC range: 1 <= VIC <= 219 (CEA-861-G), we have
+	 * to make sure we dont break HDMI2.0 sinks.
 	 */
-	if (!is_hdmi2_sink(connector) && vic > 64)
+
+	if (!is_hdmi21_sink(connector) && !is_hdmi2_sink(connector) && vic > 64)
+		return 0;
+
+	if (!is_hdmi21_sink(connector) && vic > 107)
+		return 0;
+
+	if (vic > 219)
 		return 0;
 
 	return vic;
-- 
2.25.1