[PATCH v3 10/10] ARM: tegra: pcie: Add device tree support

Bjorn Helgaas bhelgaas at google.com
Wed Aug 15 16:48:15 EDT 2012


On Wed, Aug 15, 2012 at 2:25 PM, Arnd Bergmann <arnd at arndb.de> wrote:
> On Wednesday 15 August 2012, Thierry Reding wrote:
>> Yes, that was my understanding as well. So currently I haven't seen any
>> problems with this because I only use one of the two host bridges. But I
>> suppose I should add code to initialize the bus number aperture properly
>> either via platform device resources (for the non-DT case) and the
>> device tree otherwise.
>
> I think when we last discussed this, the assumption was that each
> root port has its own config space range and its own pci domain,
> so you don't have to worry about bus apertures because each root port
> can then have all 255 bus numbers. Has that turned out to be incorrect
> now?

If that's the case, there's no problem.  I just want to be explicit
about the host bridge bus number aperture because I'd like to make
pci_scan_root_bus() fail if no aperture is supplied or if the aperture
overlaps with something we've already seen.  I don't know if that
means you want to add a domain and [bus 00-ff] range in device tree,
or if you want to make some device tree rule about every host bridge
being in its own domain, or what.

Bjorn



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