Re: FTP stalls on tl0 on Challenge S

[George Harvey <fr30%dial.pipex.com@localhost>]

On Fri, 26 Mar 2010 20:30:22 -0700
"Stephen M. Rumble" <rumble%cs.stanford.edu@localhost> wrote:

> On Mar 26, 2010, at 7:43 PM, Stephen M. Rumble wrote:
> 
> > On Mar 26, 2010, at 3:21 PM, George Harvey wrote:
> > 
> >> Good call, the bad checksum count does increment. Wireshark says the IP
> >> and TCP checksums are good so that tends to confirm the problem's in
> >> the SGI.
> > 
> > Hi George,
> > 
> > Sounds like we may be messing up the receive DMA. Could you try the 
> > attached patch (against src/sys/dev/pci/if_tl.c)? I recall correctly, I 
> > eventually discovered that this nic's pci<->gio bus bridge can't DMA across 
> > page boundaries. I fixed the TX side, but for some reason neglected RX. I 
> > don't recall if I just forgot to handle the RX case and it worked well 
> > enough, or if I believed it wasn't necessary for some reason.
> 
> Hrm. Actually, just the RX descriptor ring boundary restriction was missed, 
> not the RX buffers themselves. It might still be worth trying the patch if 
> it's quick to do, but it doesn't look like the glaring omission I thought it 
> was.

It will probably be Monday before I get a chance to build a kernel but
I'll certainly give it a try and let you know how it goes.

Thanks,
George