drm/radeon/dp: return -EIO for flags not zero case
commit
f6be5e64500abbba44e191e1ca0f3366c7d0291b upstream.
If there are error flags in the aux transaction return
-EIO rather than -EBUSY. -EIO restarts the whole transaction
while -EBUSY jus retries. Fixes problematic aux transfers.
Bug:
https://bugs.freedesktop.org/show_bug.cgi?id=80684
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
[bwh: Backported to 3.2: error code is returned directly here]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>