[PATCH 0/3] Add PCI domain support to R-Car drivers
Bjorn Helgaas
bhelgaas at google.com
Mon Sep 22 14:00:38 PDT 2014
On Mon, Sep 22, 2014 at 10:51:07AM +0100, Phil Edworthy wrote:
> The Renesas R-Car devices (r8a7790 and r8a7791) use two PCI controller drivers,
> one for an external PCIe slot, the other for an internal PCI bridge to USB
> controllers.
>
> However, they currently do not work at the same time as they use the same PCI
> domain and use the same root bus number. We can't use different root bus numbers
> due to the way root bus numbers are assigned in pcibios_init_hw() in
> arch/arm/kernel/bios32.c.
>
> Since the two PCI controllers are completely independent, I think it makes sense
> to use different PCI domains for them.
>
> I've marked the third patch as RFC as I am not sure of the impact of enabling
> PCI domains for all ARM devices. In the march to 'one kernel to rule them all',
> I steered clear of mach specific changes.
>
> These patches require the following patch from Liviu Dudau:
> [PATCH v11 07/10] OF: Introduce helper function for getting PCI domain_nr
> Based on comments on this patch from Jason Gunthorpe, there is still the issue
> that the domain numbers may change depending on the ordering at probe time.
> However, this can be fixed later on by adding the entries in the DT files.
>
>
> Phil Edworthy (3):
> PCI: rcar-pcie: Add call to get domain nr
> PCI: rcar-internal-pci: Add call to get domain nr
> ARM: Enable PCI domains
I'm deferring these for now because they depend on Liviu's work, which I
haven't merged yet, and I suspect some minor adaptation will be required
here.
For what it's worth, I agree with Rob's hesitation about mixing lookup with
domain number allocation in of_pci_get_domain_nr(). That seems
unnecessarily complicated.
> arch/arm/Kconfig | 2 +-
> drivers/pci/host/pci-rcar-gen2.c | 6 ++++++
> drivers/pci/host/pcie-rcar.c | 9 ++++++---
> 3 files changed, 13 insertions(+), 4 deletions(-)
>
> --
> 2.1.0
>
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