[parisc-linux] Re: Strange serial behaviour on C160

Peter Mottram peter@petescaff.com
Fri, 22 Feb 2002 17:58:04 +0100 (CET)

I now have 2.4.17-pa28 running on my C160 & things have improved but are
not yet perfect as I still have three serial ports......

/dev/ttyS0, UART: 16550A, Port: 0x0000, IRQ: 90
/dev/ttyS1, UART: 16550A, Port: 0x0000, IRQ: 121
/dev/ttyS2, UART: 16550A, Port: 0x0000, IRQ: 121

Of these devices the functional ports are 0 & 2. The weird speed problems
have gone away so I can use my second serial port without problems - it is
just a little odd that the rogue ttyS1 still shows up.

Anything I can usefully look at to try to help sort this out?


On Wed, 20 Feb 2002, Matthew Wilcox wrote:

> On Wed, Feb 20, 2002 at 06:59:00PM +0100, Peter Mottram wrote:
> > Before upgrading from HP-UX to Linux I had two perfectly functioning
> > serial ports on my C160. I now appear to have THREE serial ports -
> > ttyS[0-2].
> Hehe.. yeah, that was the case for quite a long time :-)
> > ttyS0 works perfectly
> > ttyS1 goes somewhere - not found where yet
> > ttyS2 goes to my second serial port but does not work at all well. A
> > simple cat of a file to the device results in the file appearing on a
> > terminal just a few characters at a time & incredibly slowly. All serial
> > ports have the same settings & ttyS0 has no problems (I use it for the
> > console).
> If you could upgrade to the latest kernel, you will find the additional
> serial port gone again.  I hadn't heard about the speed problems before,
> so if you could tell me whether they're still present with most-recent
> kernel, that would be very helpful.  Thanks!