drm/amd/display: No display after resume from WB/CB

First MST sideband message returns AUX_RET_ERROR_HPD_DISCON
on certain intel platform. Aux transaction considered failure
if HPD unexpected pulled low. The actual aux transaction success
in such case, hence do not return error.

Not returning error when AUX_RET_ERROR_HPD_DISCON detected
on the first sideband message.

v2: squash in fix (Alex)

Reviewed-by: Jerry Zuo <Jerry.Zuo@amd.com>
Acked-by: Brian Chang <Brian.Chang@amd.com>
Signed-off-by: Tsung-hua Lin <Tsung-hua.Lin@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Cc: stable@vger.kernel.org
1 file changed