2.6.24.4-64 x86_64 ... New IOMMU Error Message

[Antti J. Huhtala]

to, 2008-04-03 kello 07:34 -0700, Sean Bruno kirjoitti:
> On Thu, 2008-04-03 at 12:38 +0300, Antti J. Huhtala wrote:
> > ke, 2008-04-02 kello 21:00 -0700, Sean Bruno kirjoitti:
> > > I seem to remember this error message a long time ago on my dual
> > > opteron, but then it went away.  Now it has reappeared with the latest
> > > kernel update:
> > > 
> > > Checking aperture...
> > > CPU 0: aperture @ c000000 size 32 MB
> > > Aperture too small (32 MB)
> > > No AGP bridge found
> > > Your BIOS doesn't leave a aperture memory hole
> > > Please enable the IOMMU option in the BIOS setup
> > > This costs you 64 MB of RAM
> > > Mapping aperture over 65536 KB of RAM @ c000000
> > > Memory: 6129976k/7340032k available (2491k kernel code, 161028k
> > > reserved, 1390k data, 332k init)
> > > SLUB: Genslabs=12, HWalign=64, Order=0-1, MinObjects=4, CPUs=4, Nodes=2
> > > Calibrating delay using timer specific routine.. 4021.83 BogoMIPS
> > > (lpj=2010919)
> > > 
> > > 
> > > lspci output --> http://consultcsg.com/lspci.out
> > > full dmesg output --> http://consultcsg.com/dmesg.out
> > > 
> > A similar problem has been bothering my box since last August, see
> > 
> > https://bugzilla.redhat.com/show_bug.cgi?id=278721
> > 
> > However, when the box is rebooted (warm boot) the problem disappears and
> > the 128 M reserved for AGP aperture in BIOS is found and used. The
> > problem is there only if and when the box is cold-booted.
> > My box has an ATI Radeon 9200 PRO VGA compatible controller with nvidia
> > chipset. The motherboard (Asus K8N) BIOS has no IOMMU option.
> > 
> > HTH, Antti
> > 
> > 
> > > 
> > 
> In my scenario I didn't cold boot, it was just a kernel update and then
> a reboot.
> 
All right, then it's not quite the same problem. Also, in my case when I
cold-boot, _no_ AGP aperture is found. Only when I reboot the 128 MB of
memory reserved in BIOS for accelerated graphics is found.
On the other hand, in the dmesg exerpt above it is said:
"CPU 0: aperture @ c000000 size 32 MB" and
"Aperture too small (32 MB)"
This seems to indicate that 32 MB *is* reserved for AGP aperture in your
motherboard BIOS. Have you tried changing that to 64 MB or 128 MB?

> Also, I don't even have an AGP slot.  So that confuses me even more.

When you say "slot", are you referring to a connector reserved for a
graphics card in the motherboard? According to eg. 
http://www.hardwarezone.com/articles/view.php?cid=25&id=1661
there *is* an expansion slot called "PCI Express graphics x16 slot".

"AGP aperture" is not a hardware connector but a portion of RAM reserved
for accelerated graphics. You can change the amount of RAM reserved in a
BIOS setting. In K8N BIOS setup this is done in
"Advanced->Chipset->Aperture Size".

> The Asus K8N-DL is a PCI-E Graphics Motherboard.

> Sean
> 
Good luck!

Antti