[PATCH] powerpc: Fix something

[Benjamin Herrenschmidt]

On Mon, 2008-12-29 at 11:12 +1100, Paul Mackerras wrote:
> X has been failing to start on my quad G5 powermac since commit
> 1fd0f52583a85b21a394201b007bc1ee104b235d ("powerpc: Fix domain numbers
> in /proc on 64-bit") went in.  The reason is that the change allows X
> to see the PCI-PCI bridge above the video card (previously it was
> obscured by the fact that there were two "00" directories in
> /proc/bus/pci), and the pciconfig_iobase system call on the bridge is
> failing because of a hack that we have to return information about the
> AGP bus when X asks about bus 0.  This machine doesn't have an AGP bus
> (it has PCI Express) and so the pciconfig_iobase call is returning -1,
> which ultimately causes X to fail to start.
> 
> This fixes it by checking that we have an AGP bridge before
> redirecting the pciconfig_iobase call to return information about the
> AGP bus.  With this, X starts successfully both on a quad G5 with
> PCI Express and on an older dual G5 with AGP.
> 
> Signed-off-by: Paul Mackerras <paulus at samba.org>

Acked-by: Benjamin Herrenschmidt <benh at kernel.crashing.org>
---

(With fixed subject of course :-)

Cheers,
Ben.