Re: NetBSD 5.0.1 Networking Message

[Erik Winkler <ewinkler%erols.com@localhost>]

I am still getting the "transmit underrun" errors plus the following  
as well:

/netbsd: ex1:  transmit underrun (9000) @20, new threshold is 40
/netbsd: ex1:  transmit underrun (9000) @40
/netbsd: ex1:  transmit underrun (9000) @40
/netbsd: ex1:  transmit underrun (9000) @40, new threshold is 60

Seems strange since the system has a 1 Ghz CPU and 768 MB of RAM.  I  
never had this error with NetBSD 3.0 and it has only just appeared  
with NetBSD 4.0 and 5.0.  Any ideas where to look in the kernel code?

Thanks,

Erik

On Aug 16, 2009, at 4:33 PM, David Young wrote:

> On Sun, Aug 16, 2009 at 01:33:05PM +0200, Manuel Bouyer wrote:
> > On Sat, Aug 15, 2009 at 06:39:41PM -0400, Erik Winkler wrote:
> > > I am running NetBSD 5.0.1 (Generic PPC Kernel) on PowerMac 7600  
> > > with a
> > > powerpc 7455 processor upgrade card running at 1 Ghz.  I have 2 of  
> > > the
> > > following ethernet cards installed (per NetBSD dmesg output):
> > >
> > > 3Com 3c905B-TX 10/100 Ethernet (rev. 0x30)
> > >
> > > For some reason I keep getting the following messages and I don't  
> > > see
> > > the cause:
> > >
> > > ex1:  transmit underrun (9000) @20
> >
> > This means the 3com chip couldn't get data fast enough from the PCI  
> > bus.
> > THis is usually because another device (or possibly the CPU) holds  
> > the PCI
> > bus for too long. It's probably happening only once in a while (no  
> > more than
> > once every 256 packets) otherwise it would have bumped the TX  
> > threshold.