Hello!
When websocket client send uncompressed message (with RSV1 = 0) to the channel (with accepted permessage-deflate extension) connection aborting with status code = 1006 and error log contains this message:
2017/02/28 12:04:52 [error] 20226#20226: *6 inflate error : -3 while upgraded connection, client: 10.36.7.197, server: 10.36.7.196, request: "GET /ws_stub HTTP/1.1", host: "10.36.7.196:8090"

But, according RFC 7692, client may send uncompressed message with permessage-deflate enabled, unsetting RSV1 flag.