Use the raw video PBN in ALLOCATE_PAYLOAD requests while keeping the
TU-aligned PBN for source hardware programming. Also track the PBN
actually allocated by downstream branches and use it in later bandwidth
checks.

The series was tested with a three-display PS8650 MST daisy chain.

Changes in v3:
- Preserve allocated_pbn when recalculating an active payload; clear it
  only when releasing the payload.
- Patch 1 is unchanged.

Xiao Lu (2):
  drm/i915/dp: fix PBN in ALLOCATE_PAYLOAD request to use actual video
    bandwidth
  drm/dp_mst: Track allocated_pbn from ALLOCATE_PAYLOAD down-reply

 drivers/gpu/drm/display/drm_dp_mst_topology.c | 17 +++++++---
 drivers/gpu/drm/i915/display/intel_dp_mst.c   | 33 ++++++++++++++-----
 include/drm/display/drm_dp_mst_helper.h       | 10 ++++++
 3 files changed, 46 insertions(+), 14 deletions(-)

-- 
2.43.0