Jason Thorpe wrote:

> On Tue, 21 Apr 1998 14:42:50 -0700
>  Chuck <nospam@best.com> wrote:
>
>  > Sometimes you have to share interrupts.  This system has an IDE
> disk
>  > and four quad-port ethernet cards.
>  >
>  > Below is `dmesg` from the system which is having problems and
>  > producing this error message:
>  >   Apr 21 14:21:34 smdls4 /netbsd: de0: abnormal interrupt: transmit
> underflow
>  >   (raising TX threshold to 96|256)
>
> Don't worry about this too much...  It basically means that the kernel
>
> wasn't feeding the Tulip buffers fast enough for 100Mbit transfers.
> By
> raising the TX threshold, the driver gives the Tulip more buffers for
> every TX complete interrupt...
>

Hmmm...On the machine that I am working with, things are still working
ok at this point
but when the following message appears...


       Apr 15 17:33:06 smdls3 /netbsd: de0: abnormal interrupt: transmit

           underflow (switching to store-and-forward mode)

The transfer slows to a crawl, even a ping to that port takes 1 sec to
come back.
(for the purpose of this test there is nothing else going on on this net
segment)
After the transfer is finished things do not "come back" that is the
port stays "slow"

> You can probably alter this configuration via the BIOS.  But it's
> probably an artifact of how the BIOS swizzles the interrupts through
> the PCI-PCI bridges...
>
> If you tell the BIOS to reserve IRQ 10 for the ISA (i.e. PnP WSS :-),
> then it will probably more evenly divide them between 9 and 11.

Thanks I'll give this a try...

Al Urbaitis
Image Guided Surgery
Picker International
Albuquerque New Mexico
505-480-5163
aurbaiti@servecom.picker.com