commit8f4bdbc8e9upstream. This reverts commit58c3b3341c. [WHY & HOW] The writeback series cause a regression in thunderbolt display. Signed-off-by: Alex Hung <alex.hung@amd.com> Reviewed-by: Harry Wentland <harry.wentland@amd.com> Signed-off-by: Alex Deucher <alexander.deucher@amd.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>