From: Adam Jackson <ajax@redhat.com>
Date: Tue, 25 May 2010 20:33:09 +0000 (-0400)
Subject: drm/edid: Allow non-fatal checksum errors in CEA blocks
X-Git-Url: http://git.lede-project.org./?a=commitdiff_plain;h=4a638b4e38234233f5c7e6705662fbc0b58d80c2;p=openwrt%2Fstaging%2Fblogic.git

drm/edid: Allow non-fatal checksum errors in CEA blocks

Switches will try to update the topology address and not correctly fix
up the checksum, so just let it slide.

https://bugs.freedesktop.org/28229

Signed-off-by: Adam Jackson <ajax@redhat.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
---

diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c
index f569ae88ab38..c1981861bbbd 100644
--- a/drivers/gpu/drm/drm_edid.c
+++ b/drivers/gpu/drm/drm_edid.c
@@ -147,7 +147,10 @@ drm_edid_block_valid(u8 *raw_edid)
 		csum += raw_edid[i];
 	if (csum) {
 		DRM_ERROR("EDID checksum is invalid, remainder is %d\n", csum);
-		goto bad;
+
+		/* allow CEA to slide through, switches mangle this */
+		if (raw_edid[0] != 0x02)
+			goto bad;
 	}
 
 	/* per-block-type checks */