Re: TTY_FLIPBUF_SIZE too low causing dataloss on too fast serial lines?

Pavel Machek (pavel@atrey.karlin.mff.cuni.cz)
Wed, 26 May 1999 14:14:05 +0200


Hi!

> I tried implementing 1Mbit irda driver as a tty (same as serials
> are). I _think_ I've hit the limit of TTY_FLIPBUF_SIZE. Is it
> possible? I assume flipbufs are flushed every 10ms or so (am I right?);
> in such case situation is pretty bad: that means 50K/sec max and
> modern serial ports can do up-to twice as much. From reading sources I
> _think_ that TTY_FLIPBUF_SIZE can not be easily increased....
>
> Nope, it can't be easily increased without making some relatively major
> changes to the tty driver. I've been meaning to do this so that the you
> can use a bigger flip buffer size, where it's necesasry, though.
>
> One question though is how is your irda driver grabbing the characters?
> Is it grabbing them all at interrupt time, or is it polling like

All at interrupt time. I wonder how do you solve this problem with
serial ports: these days serials can be easily driven at speeds close
to 1Mbit... (I'm talking about dumb on-board serials like NS PC87108).
Pavel

-- 
The best software in life is free (not shareware)!		Pavel
GCM d? s-: !g p?:+ au- a--@ w+ v- C++@ UL+++ L++ N++ E++ W--- M- Y- R+

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