Re: RTS/CTS flow control

[mhitch%gemini.oscs.montana.edu@localhost (Michael L. Hitch)]

On Jul 15, 10:58am, Ignatios Souvatzis wrote:
> Don Phillips <bsd%blkhole.resun.com@localhost> wrote:
> > Does anybody know if RTS/CTS flow control has been fully implemented in
> > the serial port (ser.c) and/or A2232 multi-port serial cards?  If it
> > hasn't and the modem on the port is set for hardware flow control, it
> > might explain some of the overruns that I'm seeing (silo overflows.)  I am
> > aware of the options to change the size of the silos, and to defer the
> > level 6 interrupts, but deferring the level 6 interrupts seems to have the
> > unpleasant side effect of really messing up the clock.
...
> The only thing it does is read the data byte and status bits from the 
> hardware, as one 16bit read, and write them to a ringbuffer without looking
> at them, as one 16bit write. Nothing more (this is why the NetBSD serial
> driver performs better than the Commodore serial driver :-).

  The serial receive interrupt also checks for an impending overflow of the
ring buffer and unconditionally drops RTS.

Michael

-- 
Michael L. Hitch                        osymh%montana.edu@localhost
Computer Consultant
Information Technology Center
Montana State University        Bozeman, MT     USA