Re: Regression: ftdi_sio is slow (since Wed Oct 10 15:05:06 2012)

[Stas Sergeev]

04.05.2013 15:15, Johan Hovold ÐÐÑÐÑ:
> The query takes longer than the transmit at decent baudrates (>=38k)
> and under the assumption that flow control isn't causing any delays.
>
> But you do have a point, and I have been meaning to look into whether
> the added overhead of checking the hardware buffers could be mitigated
> by adding wait_until_sent support to usb-serial. This way the we would
> only query the hardware buffers on tty_wait_until_sent (e.g. at close)
> and select and TIOCMOUTQ would not suffer. This is also the way things
> are handled in serial_core.
Thanks for taking a look.
Indeed, it seems .wait_until_sent is the best candidate for that
kind of things, and the patch in question would even match its
description be it using .wait_until_sent and not .chars_in_buffer.
Please count on testing your patches here when they are ready.
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