From: Imre Deak <imre.deak@xxxxxxxxx> commit 1d082618bbf3b6755b8cc68c0a8122af2842d593 upstream. If the sink gets disconnected during receiving a multi-packet DP MST AUX down-reply/up-request sideband message, the state keeping track of which packets have been received already is not reset. This results in a failed sanity check for the subsequent message packet received after a sink is reconnected (due to the pending message not yet completed with an end-of-message-transfer packet), indicated by the "sideband msg set header failed" error. Fix the above by resetting the up/down message reception state after a disconnect event. Cc: Lyude Paul <lyude@xxxxxxxxxx> Cc: <stable@xxxxxxxxxxxxxxx> # v3.17+ Signed-off-by: Imre Deak <imre.deak@xxxxxxxxx> Reviewed-by: Lyude Paul <lyude@xxxxxxxxxx> Link: https://patchwork.freedesktop.org/patch/msgid/20221214184258.2869417-1-imre.deak@xxxxxxxxx Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/gpu/drm/drm_dp_mst_topology.c | 3 +++ 1 file changed, 3 insertions(+) --- a/drivers/gpu/drm/drm_dp_mst_topology.c +++ b/drivers/gpu/drm/drm_dp_mst_topology.c @@ -3769,6 +3769,9 @@ int drm_dp_mst_topology_mgr_set_mst(stru set_bit(0, &mgr->payload_mask); mgr->vcpi_mask = 0; mgr->payload_id_table_cleared = false; + + memset(&mgr->down_rep_recv, 0, sizeof(mgr->down_rep_recv)); + memset(&mgr->up_req_recv, 0, sizeof(mgr->up_req_recv)); } out_unlock:
