• Lyude's avatar
    drm/radeon: Retry DDC probing on DVI on failure if we got an HPD interrupt · cb5d4166
    Lyude authored
    HPD signals on DVI ports can be fired off before the pins required for
    DDC probing actually make contact, due to the pins for HPD making
    contact first. This results in a HPD signal being asserted but DDC
    probing failing, resulting in hotplugging occasionally failing.
    
    This is somewhat rare on most cards (depending on what angle you plug
    the DVI connector in), but on some cards it happens constantly. The
    Radeon R5 on the machine used for testing this patch for instance, runs
    into this issue just about every time I try to hotplug a DVI monitor and
    as a result hotplugging almost never works.
    
    Rescheduling the hotplug work for a second when we run into an HPD
    signal with a failing DDC probe usually gives enough time for the rest
    of the connector's pins to make contact, and fixes this issue.
    Reviewed-by: default avatarChristian König <christian.koenig@amd.com>
    Signed-off-by: default avatarLyude <cpaul@redhat.com>
    Signed-off-by: default avatarAlex Deucher <alexander.deucher@amd.com>
    cb5d4166
radeon_connectors.c 82.1 KB