The following sequence can occur: sink_EndOfStream, lock stream_cs, renderer sink_eos, strmbase_passthrough_eos, IMediaSeeking_GetStopPosition, MediaSeekingPassThru_GetStopPosition, get_connected, IPin_ConnectedTo, lock filter_cs And at the same time: filter_Stop, lock filter_cs, dmo_wrapper_cleanup_stream, lock stream_cs Resulting in deadlock. This can occur in Space Engineers. dmo_wrapper_cleanup_stream() locks stream_cs to access `pin.peer` and `pin.pAllocator`, which are normally protected by filter_cs, but this lock was added to fix a test failure, so I don't know if there's an alternative. I'm concerned about the possible performance impact of removing stream_cs though. -- https://gitlab.winehq.org/wine/wine/-/merge_requests/8712