Re: Problems with

Darrin R. Smith (
Thu, 22 Aug 1996 21:27:41 -0400

Theodore Y. Ts'o wrote:
> Date: Tue, 06 Aug 1996 19:42:55 -0400
> From: "Darrin R. Smith" <>
> I am having some trouble with a custom serial port setup on
> my machine. Specifically, I have a mouse on cua0(com1), modem on
> cua1(com2), and a Sparc IPC connected to cua3(com4) for use as the
> console. The setup is as follows:
> cua0 0x3f8 4 16550A
> cua1 0x2f8 3 16550A
> cua3 0x2e8 5 16550A
> The problem is that new characters arriving on cua3 are not
> generating any interrupts as can be seen in /proc/interrupts:
> I have been setting the parameters on this port using setserial
> for quite a while and I can't seem to get it to work. I also recompiled
> minicom suspecting that something might have broke between 1.2.13 and
> now, but it didn't have any effect.
> It sounds like you didn't set the dip switch settings on your COM4 board
> to actually use IRQ 5. You realize that you have to change more than
> just the settiongs in rc.serial and setserial, right? You actually have
> to configure the hardware to use IRQ 5.....
> - Ted

ok, my last post on this apparently didn't make it to the list for some
reason -- so here is the latest status again.

I did a double-check on the hardware this last weekend. Nothing
is out of order there -- No devices conflict, the serial port is setup
properly(this is a DTC 2278E board in case anyone wants to know).

I tried re-compiling the kernel with the proper values set in
serial.c, and I stopped using the setserial utility to set the parameters.
The kernel prints out the right information on bootup, but the same
problem persists. Using setserial doesn't appear to make a difference in
this re-compiled kernel, either.

At this point, I am open to more suggestions. Off the top of my
head, I would probably say that maybe we aren't initializing the card
properly, or we've found a bug in the DTC 2278 hardware, but I would also
be willing to admit I could be on shaky ground with this diagnosis(since
the mouse on com1 via the DTC works fine). TIA.


FAQ Suggestions:
   Q:  I upgraded without reading release notes, now my system's broke -
   A:  What the @!#* did you expect?
        (this assumes that someone reads the faq, of course ;)