• Alex Deucher's avatar
    drm/radeon/kms: fix shared ddc harder · 42f14c4b
    Alex Deucher authored
    This fixes a regression caused by b2ea4aa6
    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: default avatarAlex Deucher <alexdeucher@gmail.com>
    Cc: stable@kernel.org
    Signed-off-by: default avatarDave Airlie <airlied@redhat.com>
    42f14c4b
radeon_connectors.c 43.6 KB