Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933461AbaKMPWo (ORCPT ); Thu, 13 Nov 2014 10:22:44 -0500 Received: from foss-mx-na.foss.arm.com ([217.140.108.86]:57636 "EHLO foss-mx-na.foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933088AbaKMPWm (ORCPT ); Thu, 13 Nov 2014 10:22:42 -0500 Date: Thu, 13 Nov 2014 15:22:43 +0000 From: Lorenzo Pieralisi To: Liviu Dudau Cc: Will Deacon , "suravee.suthikulpanit@amd.com" , "bhelgaas@google.com" , "linux-pci@vger.kernel.org" , "linux-arm-kernel@lists.infradead.org" , "linux-kernel@vger.kernel.org" Subject: Re: [PATCH 2/2] PCI: generic: Add set_msi_parent callback Message-ID: <20141113152243.GB9726@red-moon> References: <1415647480-3320-1-git-send-email-suravee.suthikulpanit@amd.com> <1415647480-3320-3-git-send-email-suravee.suthikulpanit@amd.com> <20141111112424.GB16265@arm.com> <20141111115227.GF12037@e106497-lin.cambridge.arm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20141111115227.GF12037@e106497-lin.cambridge.arm.com> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Nov 11, 2014 at 11:52:27AM +0000, Liviu Dudau wrote: > On Tue, Nov 11, 2014 at 11:24:24AM +0000, Will Deacon wrote: > > Hi Suravee, > > > > On Mon, Nov 10, 2014 at 07:24:40PM +0000, suravee.suthikulpanit@amd.com wrote: > > > From: Suravee Suthikulpanit > > > > > > This patch implement set_msi_parent callback for PCI generic host controller. > > > > > > Cc: Bjorn Helgass > > > Cc: Liviu Dudau > > > Cc: Lorenzo Pieralisi > > > Signed-off-by: Suravee Suthikulpanit > > > --- > > > drivers/pci/host/pci-host-generic.c | 14 ++++++++++++++ > > > 1 file changed, 14 insertions(+) > > > > > > diff --git a/drivers/pci/host/pci-host-generic.c b/drivers/pci/host/pci-host-generic.c > > > index 036ab1b..f9bb97a 100644 > > > --- a/drivers/pci/host/pci-host-generic.c > > > +++ b/drivers/pci/host/pci-host-generic.c > > > @@ -42,6 +42,7 @@ struct gen_pci { > > > struct pci_host_bridge host; > > > struct gen_pci_cfg_windows cfg; > > > struct list_head resources; > > > + struct msi_chip *mchip; > > > }; > > > > > > #ifdef CONFIG_ARM > > > @@ -128,9 +129,19 @@ static int gen_pci_config_write(struct pci_bus *bus, unsigned int devfn, > > > return PCIBIOS_SUCCESSFUL; > > > } > > > > > > +static int gen_pci_set_msi_parent(struct pci_bus *bus) > > > +{ > > > + struct gen_pci *pci = bus_to_gen_pci(bus); > > > + > > > + bus->msi = pci->mchip; > > > + > > > + return PCIBIOS_SUCCESSFUL; > > > +} > > > > I don't think this makes much sense a host controller callback. Why can't > > bus->msi be set in generic code? > > Because of the current way in which a bus gets created and them immediately used for > scanning devices if you use pci_scan_root_bus(). Alternative is to use pci_create_root_bus() > and increase your code size with the body of pci_scan_root_bus(). > > Solution is to have pci_host_bridge holding the msi_chip pointer and that gets created > before root bus, with pci_scan_root_bus() now having all the info needed to do successful > setup of scanned devices. Why can't we add a hook like pci_bus_assign_domain_nr(), say: pci_bus_msi_init() in pci_create_root_bus() that does what Suravee wants in a generic way ? What am I missing ? Lorenzo > > Best regards, > Liviu > > > > > > static struct pci_ops gen_pci_ops = { > > > .read = gen_pci_config_read, > > > .write = gen_pci_config_write, > > > + .set_msi_parent = gen_pci_set_msi_parent, > > > }; > > > > > > static const struct of_device_id gen_pci_of_match[] = { > > > @@ -313,6 +324,9 @@ static int gen_pci_probe(struct platform_device *pdev) > > > return err; > > > } > > > > > > + pci->mchip = of_pci_find_msi_chip_by_node(of_parse_phandle(np, > > > + "msi-parent", 0)); > > > > This bit should be in the generic of_pci.c code and not duplicated for > > each host controller. > > > > Will > > > > -- > ==================== > | I would like to | > | fix the world, | > | but they're not | > | giving me the | > \ source code! / > --------------- > ¯\_(ツ)_/¯ -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/