David A. Ranch <[EMAIL PROTECTED]> wrote:
>
> >1) The 16650 serial <-> modem isn't reliable at 230400 (using cable
> > supplied with modem.
>
> I've heard that Linux's setserial has problems with 16650s.
I don't know about this, but I do know that a 16650 is not supported by
Linux 2.0, unless you have some patches I don't know about. I am forced
to run Linux 2.1, which has full support for the 16650. Not that
there's anything wrong with the 2.1 kernel; it works just fine for me.
> >2) My old 486SX can't keep up with 230400 even when using a 16650
>
> I bet thats an issue too.
Be advised that there are multiple "versions" of the 16650 chip, and
that some work better than others. A real 16650 chip has a 32-byte FIFO
on it, which means that if your machine can handle 115200 bps on a
16550, then it should be able to handle 230400 bps on a 16650 just as
easily. However, if your 16650 chip is either not supported, or not the
type that Linux wants to handle, then its FIFO will be disabled, and it
will be treated like a 16450. This will result in terrible serial
performance, dropped characters, horrendous interrupt rates, etc.
So, you either have nothing to worry about, or a lot to worry about, if
you have a 16650 chip. :)
A 486SX shouldn't have any trouble, *if* your FIFO is enabled on the
chip. Do you know if this is the case?
Here's what my kernel reports (and what you want to see):
ttyS00 at 0x03f8 (irq = 4) is a ST16650V2
ttyS01 at 0x02f8 (irq = 3) is a ST16650V2
--
[EMAIL PROTECTED] (Fuzzy Fox) || "Nothing takes the taste out of peanut
sometimes known as David DeSimone || butter quite like unrequited love."
http://www.dallas.net/~fox/ || -- Charlie Brown
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