gma: Probe sibling ports for improper connected displays

If an HDMI/DP display is detected, probe the sibling port that shares
physical pins too and bail out if something is detected. This is a
precaution for adapters that expose the pins of a port for both HDMI/
DVI and DP (like some ThinkPad docks). A user might have attached both
by accident and there are rumors of displays that got fried by apply-
ing the wrong signal.

Change-Id: I276ad55a353d60389bc36724d8af37b158ae4599
Signed-off-by: Nico Huber <nico.h@gmx.de>
Reviewed-on: https://review.coreboot.org/17755
Reviewed-by: Arthur Heymans <arthur@aheymans.xyz>
1 file changed
tree: 19548438d80ae32b7b52470c84db163f85ad9083
  1. common/
  2. configs/
  3. .gitignore
  4. COPYING
  5. Makefile
  6. Makefile.inc
  7. TODO