Re: [PATCH v8 3/9] pci: Introduce pci_register_io_range() helper function.

From: Arnd Bergmann
Date: Wed Jul 09 2014 - 02:34:01 EST


On Wednesday 09 July 2014, Liviu Dudau wrote:
> > Maybe that assumption is guaranteed by OF, but it doesn't hold for ACPI;
> > ACPI can describe several I/O port apertures for a single bridge, each
> > associated with a different CPU physical memory region.
>
> That is actually a good catch, I've completely missed the fact that
> io_range->pci_addr could be non-zero.

Hmm, that's what I thought in my initial review, but you convinced me
that it's actually correct later on, and I still believe it is. Maybe
now you got confused by your own code?

Please have another look, I think your code in pci_host_bridge_of_get_ranges
sufficiently handles the registration to the PCI code with the correct
io_offset. The only thing that we might want to add is to record the
PCI address along with the bridge->io_base: For the host driver to
set up the mapping window correctly, you either need both of them, or
you assume they are already set up.

Arnd
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