Machine check during PCI scan on PMac G5

[Benjamin Herrenschmidt]

> I'm suprised, I'm not sure it's actually GEM (Andreas, is the Sungem
> properly functionning on this box after this fix ?). I think the
> numbering of the Shims can change from firmware to firmware, it's
> more probably one of the USBs. There is code in pmac_feature.c to
> power up the GEM (but only if it has a device-node).

Ok, after digging in the OF code, it seems that on machines without
a PCI-X bridge, shim 6 is just not used and the stuff is really upset
when we probe it. K2 is a weird beast that needs care...

Ben.