drm/radeon/kms: fix shared ddc harder
This fixes a regression caused by b2ea4aa67bfd084834edd070e0a4a47857d6db59
due to the way shared ddc with multiple digital connectors was handled.
You generally have two cases where DDC lines are shared:
- HDMI + VGA
- HDMI + DVI-D
HDMI + VGA is easy to deal with because you can check the EDID for the
to see if the attached monitor is digital. A shared DDC line with two
digital connectors is more complex. You can't use the hdmi bits in the
EDID since they may not be there with DVI<->HDMI adapters. In this case
all we can do is check the HPD pins to see which is connected as we have
no way of knowing using the EDID.
Reported-by: trapdoor6@gmail.com
Signed-off-by: Alex Deucher <alexdeucher@gmail.com>
Cc: stable@kernel.org
Signed-off-by: Dave Airlie <airlied@redhat.com>
1 file changed