diff mbox series

[05/19] common: edid: Search for valid timing in extension block

Message ID 20210223204631.1609597-6-jernej.skrabec@siol.net
State New
Delegated to: Andre Przywara
Headers show
Series video: sunxi: Rework DE2 driver | expand

Commit Message

Jernej Škrabec Feb. 23, 2021, 8:46 p.m. UTC
One of my monitors have only 4k@60 timing in base EDID block which is
out of range for devices with HDMI 1.4. It turns out that it has
additional detailed timings in CTA-861 Extension Block and two of them
are appropriate for HDMI 1.4.

Add additional search for valid detailed timing in extension block.

Signed-off-by: Jernej Skrabec <jernej.skrabec@siol.net>
---
 common/edid.c | 18 ++++++++++++++++++
 1 file changed, 18 insertions(+)
diff mbox series

Patch

diff --git a/common/edid.c b/common/edid.c
index a6c875d9c8e8..14d8836c360e 100644
--- a/common/edid.c
+++ b/common/edid.c
@@ -220,6 +220,24 @@  int edid_get_timing_validate(u8 *buf, int buf_size,
 	/* Look for detailed timing in base EDID */
 	found = edid_find_valid_timing(edid->monitor_details.descriptor, 4,
 				       timing, mode_valid, mode_valid_priv);
+
+	/* Look for detailed timing in CTA-861 Extension Block */
+	if (!found && edid->extension_flag && buf_size >= EDID_EXT_SIZE) {
+		struct edid_cea861_info *info =
+			(struct edid_cea861_info *)(buf + sizeof(*edid));
+
+		if (info->extension_tag == EDID_CEA861_EXTENSION_TAG) {
+			int count = EDID_CEA861_DTD_COUNT(*info);
+			int offset = info->dtd_offset;
+			int size = count * sizeof(struct edid_detailed_timing);
+
+			if (offset >= 4 && offset + size < EDID_SIZE)
+				found = edid_find_valid_timing(
+					(u8*)info + offset, count, timing,
+					mode_valid, mode_valid_priv);
+		}
+	}
+
 	if (!found)
 		return -EINVAL;