edid: Sanitize bad EDID header patterns
Some devices fail to transmit the EDID header pattern correctly. To
compensate, we patch EDID header patterns when at least six out of
the eight bytes match. We then verify the checksum over all bytes
including the patched header.
Linux does it similar and gets more displays up that way, sigh.
Change-Id: Ic63880a05e64f40dfda165bd54e708cd981f08fb
Signed-off-by: Nico Huber <nico.h@gmx.de>
Reviewed-on: https://review.coreboot.org/17493
Reviewed-by: Paul Menzel <paulepanter@users.sourceforge.net>
Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>
diff --git a/common/hw-gfx-gma-connector_info.adb b/common/hw-gfx-gma-connector_info.adb
index c5dcad2..89e0425 100644
--- a/common/hw-gfx-gma-connector_info.adb
+++ b/common/hw-gfx-gma-connector_info.adb
@@ -70,7 +70,7 @@
exit when not Success; -- don't retry if reading itself failed
pragma Debug (Debug.Put_Buffer ("EDID", Raw_EDID, Raw_EDID_Length));
- Success := EDID.Valid (Raw_EDID);
+ EDID.Sanitize (Raw_EDID, Success);
exit when Success;
end loop;
end Read_EDID;