d075bca47c
drm_dp_mst_atomic_check_mgr() should check for BW limitation starting from sink ports continuing towards the root port, so that drivers can use the @failing_port returned to resolve a BW overallocation in an ideal way. For instance from streams A,B,C in a topology A,B going through @failing_port and C not going through it, a BW overallocation of A,B due to a limit of the port must be resolved first before considering the limits of other ports closer to the root port. This way can avoid reducing the BW of stream C unnecessarily due to a BW limit closer to the root port. Based on the above swap the order of the BW check for the root port and the check for all the ports downstream of it (the latter going through the topology already in the sink->root port direction). Cc: Lyude Paul <lyude@redhat.com> Cc: dri-devel@lists.freedesktop.org Reviewed-by: Lyude Paul <lyude@redhat.com> Reviewed-by: Stanislav Lisovskiy <stanislav.lisovskiy@intel.com> Acked-by: Maxime Ripard <mripard@kernel.org> Signed-off-by: Imre Deak <imre.deak@intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20231030155843.2251023-6-imre.deak@intel.com