From mboxrd@z Thu Jan 1 00:00:00 1970 From: Bjorn Helgaas Date: Mon, 22 Sep 2014 21:00:38 +0000 Subject: Re: [PATCH 0/3] Add PCI domain support to R-Car drivers Message-Id: <20140922210038.GJ1880@google.com> List-Id: References: <1411379470-20639-1-git-send-email-phil.edworthy@renesas.com> In-Reply-To: <1411379470-20639-1-git-send-email-phil.edworthy@renesas.com> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: linux-arm-kernel@lists.infradead.org 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 >