Re: PReP and generic PCI resource assignment

On Wednesday 08 August 2001 05:27, Benjamin Herrenschmidt wrote:

quoted

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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