From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Date: Tue, 9 Feb 2016 18:02:27 +0000 From: Lorenzo Pieralisi To: Tomasz Nowicki Cc: bhelgaas@google.com, arnd@arndb.de, will.deacon@arm.com, catalin.marinas@arm.com, rjw@rjwysocki.net, hanjun.guo@linaro.org, okaya@codeaurora.org, jiang.liu@linux.intel.com, Stefano.Stabellini@eu.citrix.com, robert.richter@caviumnetworks.com, mw@semihalf.com, Liviu.Dudau@arm.com, ddaney@caviumnetworks.com, wangyijing@huawei.com, Suravee.Suthikulpanit@amd.com, msalter@redhat.com, linux-pci@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-acpi@vger.kernel.org, linux-kernel@vger.kernel.org, linaro-acpi@lists.linaro.org, jchandra@broadcom.com, jcm@redhat.com Subject: Re: [PATCH V4 11/23] pci, acpi: Move ACPI host bridge device companion assignment to core code. Message-ID: <20160209180227.GC22868@red-moon> References: <1454606941-9523-1-git-send-email-tn@semihalf.com> <1454606941-9523-12-git-send-email-tn@semihalf.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: <1454606941-9523-12-git-send-email-tn@semihalf.com> Sender: linux-acpi-owner@vger.kernel.org List-ID: On Thu, Feb 04, 2016 at 06:28:49PM +0100, Tomasz Nowicki wrote: > Currently we have two platforms (x86 & ia64) capable of PCI ACPI host > bridge initialization. They both use sysdata to pass down parent > device reference and both rely on NULL parent in pci_create_root_bus() > to validate sysdata content. > > It looks hacky and prevents us from getting some firmware specific > info for PCI host controller e.g. PCI bus domain number. > However, we overcome that blocker by passing down parent > device via pci_create_root_bus parameter (as the ACPI device type) > and using ACPI_COMPANION_SET in core code for ACPI boot method. > ACPI_COMPANION_SET is safe to run for all cases DT, ACPI and DT&ACPI. > > Suggested-by: Lorenzo Pieralisi > Signed-off-by: Tomasz Nowicki > Tested-by: Duc Dang > Tested-by: Dongdong Liu > Tested-by: Hanjun Guo > Tested-by: Graeme Gregory > Tested-by: Sinan Kaya > --- > drivers/acpi/pci_root.c | 5 ++++- > drivers/pci/probe.c | 2 ++ > 2 files changed, 6 insertions(+), 1 deletion(-) > > diff --git a/drivers/acpi/pci_root.c b/drivers/acpi/pci_root.c > index ae3fe4e..a65c8c2 100644 > --- a/drivers/acpi/pci_root.c > +++ b/drivers/acpi/pci_root.c > @@ -846,7 +846,10 @@ struct pci_bus *acpi_pci_root_create(struct acpi_pci_root *root, > > pci_acpi_root_add_resources(info); > pci_add_resource(&info->resources, &root->secondary); > - bus = pci_create_root_bus(NULL, busnum, ops->pci_ops, > + > + /* Root bridge device needs to be sure of parent ACPI type */ You can improve the comment. "pci_create_root_bus() needs to detect the parent device type, so initialize its companion data accordingly". > + ACPI_COMPANION_SET(&device->dev, device); > + bus = pci_create_root_bus(&device->dev, busnum, ops->pci_ops, > sysdata, &info->resources); > if (!bus) > goto out_release_info; > diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c > index 6d7ab9b..81dd3a2 100644 > --- a/drivers/pci/probe.c > +++ b/drivers/pci/probe.c > @@ -2100,6 +2100,8 @@ struct pci_bus *pci_create_root_bus(struct device *parent, int bus, > bridge->dev.parent = parent; > bridge->dev.release = pci_release_host_bridge_dev; > dev_set_name(&bridge->dev, "pci%04x:%02x", pci_domain_nr(b), bus); > + ACPI_COMPANION_SET(&bridge->dev, > + parent ? to_acpi_device_node(parent->fwnode) : NULL); if (parent) ACPI_COMPANION_SET(&bridge->dev, ACPI_COMPANION(parent)); ? It seems fine to me, hopefully Rafael can have a look to countercheck. Reviewed-by: Lorenzo Pieralisi > error = pcibios_root_bridge_prepare(bridge); > if (error) { > kfree(bridge); > -- > 1.9.1 >