1. 10 Dec, 2019 5 commits
  2. 09 Dec, 2019 34 commits
  3. 06 Dec, 2019 1 commit
    • Wayne Lin's avatar
      drm/dp_mst: Remove VCPI while disabling topology mgr · 64e62bdf
      Wayne Lin authored
      [Why]
      
      This patch is trying to address the issue observed when hotplug DP
      daisy chain monitors.
      
      e.g.
      src-mstb-mstb-sst -> src (unplug) mstb-mstb-sst -> src-mstb-mstb-sst
      (plug in again)
      
      Once unplug a DP MST capable device, driver will call
      drm_dp_mst_topology_mgr_set_mst() to disable MST. In this function,
      it cleans data of topology manager while disabling mst_state. However,
      it doesn't clean up the proposed_vcpis of topology manager.
      If proposed_vcpi is not reset, once plug in MST daisy chain monitors
      later, code will fail at checking port validation while trying to
      allocate payloads.
      
      When MST capable device is plugged in again and try to allocate
      payloads by calling drm_dp_update_payload_part1(), this
      function will iterate over all proposed virtual channels to see if
      any proposed VCPI's num_slots is greater than 0. If any proposed
      VCPI's num_slots is greater than 0 and the port which the
      specific virtual channel directed to is not in the topology, code then
      fails at the port validation. Since there are stale VCPI allocations
      from the previous topology enablement in proposed_vcpi[], code will fail
      at port validation and reurn EINVAL.
      
      [How]
      
      Clean up the data of stale proposed_vcpi[] and reset mgr->proposed_vcpis
      to NULL while disabling mst in drm_dp_mst_topology_mgr_set_mst().
      
      Changes since v1:
      *Add on more details in commit message to describe the issue which the
      patch is trying to fix
      Signed-off-by: default avatarWayne Lin <Wayne.Lin@amd.com>
      [added cc to stable]
      Signed-off-by: default avatarLyude Paul <lyude@redhat.com>
      Link: https://patchwork.freedesktop.org/patch/msgid/20191205090043.7580-1-Wayne.Lin@amd.com
      Cc: <stable@vger.kernel.org> # v3.17+
      64e62bdf