On (Thu) 29 Dec 2011 [15:32:14], Christian Borntraeger wrote: > > port->throttled never becomes true for qemu. > > Huh? What did I miss below? > > if (ret == -EAGAIN || (ret >= 0 && ret < buf_size)) { > virtio_serial_throttle_port(port, true);
Ah; I see what's happening. pty_chr_write() returns 0 if a client isn't yet connected. This is different from the buggy tcp_chr_write() code, which just returns 'len', i.e. a successful write. And since I've only tested with tcp/unix sockets, I couldn't see why throttling could get enabled. Amit