From mboxrd@z Thu Jan 1 00:00:00 1970 From: Suravee Suthikulpanit Subject: Re: [PATCH v12 10/12] PCI: Assign unassigned bus resources in pci_scan_root_bus() Date: Sun, 28 Sep 2014 16:16:21 -0500 Message-ID: <54287AA5.3060408@amd.com> References: <1411498874-9864-1-git-send-email-Liviu.Dudau@arm.com> <1411498874-9864-11-git-send-email-Liviu.Dudau@arm.com> <20140924011851.GD32643@bart.dudau.co.uk> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8"; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: Sender: linux-pci-owner@vger.kernel.org To: Bjorn Helgaas , Liviu Dudau Cc: Liviu Dudau , Arnd Bergmann , Rob Herring , Jason Gunthorpe , Benjamin Herrenschmidt , Catalin Marinas , Will Deacon , Russell King , linux-pci , Linus Walleij , Tanmay Inamdar , Grant Likely , Sinan Kaya , Jingoo Han , Kukjin Kim , linux-arch , LKML , Device Tree ML , LAKML List-Id: devicetree@vger.kernel.org On 09/23/2014 08:41 PM, Bjorn Helgaas wrote: > On Tue, Sep 23, 2014 at 7:18 PM, Liviu Dudau wrote: >> On Tue, Sep 23, 2014 at 08:01:12PM +0100, Liviu Dudau wrote: >>> If the firmware has not assigned all the bus resources and >>> we are not just probing the PCIe busses, it makes sense to >>> assign the unassigned resources in pci_scan_root_bus(). >>> >>> Cc: Bjorn Helgaas >>> Cc: Arnd Bergmann >>> Cc: Jason Gunthorpe >>> Cc: Rob Herring >>> Signed-off-by: Liviu Dudau >>> --- >>> drivers/pci/probe.c | 3 +++ >>> 1 file changed, 3 insertions(+) >>> >>> diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c >>> index ef891d2..508cf61 100644 >>> --- a/drivers/pci/probe.c >>> +++ b/drivers/pci/probe.c >>> @@ -1953,6 +1953,9 @@ struct pci_bus *pci_scan_root_bus(struct device *parent, int bus, >>> if (!found) >>> pci_bus_update_busn_res_end(b, max); >>> >>> + if (!pci_has_flag(PCI_PROBE_ONLY)) >>> + pci_assign_unassigned_bus_resources(b); >>> + >>> pci_bus_add_devices(b); >>> return b; >>> } >>> -- >>> 2.1.0 >>> >> >> Bjorn, >> >> If you are OK with this patch, can you let me know how do you feel about >> making pci_scan_root_bus() set up the bus->msi pointer as well? > > I'm not opposed to it, but I have the same question as for setting up > the domain: how does pci_scan_root_bus() learn what to assign to > bus->msi? It currently only gets a "void *sysdata" so there's no > obvious place to put it there. You could add a pcibios interface to > retrieve it, I suppose, but I'm starting to get uncomfortable with > adding more of those because we have such a mess of them already. > > Bjorn [Suravee] Liviu and I had a talk during Linaro Connect, and we came up with a new binding for the pcie controller called "msi-parent" which is supposed to contain phandle to the corresponded msi-controller. > >> Side note: I don't know exactly how to do it now, but setting bus->msi is >> needed by platforms that are based on my patches and want to use MSI, >> otherwise they have to open code pci_scan_root_bus() to set it. I haven't >> made any attempts to do it in this series as the GICv2m patches are not >> ready yet, but I can see the need arriving soon. [Suravee] I just sent out an RFC which implements the described binding here. https://lkml.org/lkml/2014/9/28/149 Any feedback/comments are welcome :) Thanks, Suravee