PReP and generic PCI resource assignment

[Hollis]

On Wednesday 08 August 2001 05:27, Benjamin Herrenschmidt wrote:
> >The problem is that root in this case is the PCI memory resource of the
> > host bridge, which correctly starts at 0xc0000000... but NOT in bus
> > terms. In bus terms it starts at 0x0. (CPU physical 0xc0000000 = PCI bus
> > 0x0 [IO mem].) So the new resource is assigned 0xc1000000, which is
> > written back to the BAR with pcibios_update_resource... which is way
> > wrong.
>
> The resource is in CPU space. The problem must be with
> pcibios_update_resource, which is responsible for doing the proper
> offset. If you look closely, it substracts hose->pci_mem_offset from the
> resource before writing it to the BAR.
> If your hose pci_mem_offset is wrong, then it can't work. It should be
> 0xc0000000 on PReP.

Yes, it is. I misinterpretted my debug output... :/

At any rate, relocating PCI resource 1 on this controller from 0x0 to
0x01000000 causes my VGA console to go backwards endian. I don't know why
this would be the case... Re-moving it back to 0x0 fixes the symptom. Any
ideas on why this could happen? I think VGA is all IO, no memory at all?

I'm curious about PCIBIOS_MIN_MEM... Why does that exist, and why was it
given that value?

-Hollis

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