Hi Alan, thanks, clear enough now. :)

10.08.2012 23:33, Alan Cox wrote:

	if (bytes_left < constant)
		write_wakeup


and I suspect if you made that adjustable and turned off the fifo and any
other funnies you'd at least make it work for a sufficiently rigged demo.

You suggest to turn off the fifo, sounds worrysome,
does this mean that tcdrain() and TIOCOUTQ do not
account the fifo too?
If they do quite fine with the fifo, then maybe the new
function will do too? Its basically a tcdrain(), just with
the controllable watermark I guess.