Since
fafcf94e2b5732d1e13b440291c53115d2b172e9 introduced an edid size, it seems to have broken this path.
This manifest as oops on T500 Lenovo laptops with dual graphics primarily.
Fixes: https://bugzilla.kernel.org/show_bug.cgi?id=33812
cc: stable@kernel.org
Reviewed-by: Alex Deucher <alexdeucher@gmail.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>