From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756029Ab3AMTz4 (ORCPT ); Sun, 13 Jan 2013 14:55:56 -0500 Received: from hydra.sisk.pl ([212.160.235.94]:39925 "EHLO hydra.sisk.pl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755984Ab3AMTzy (ORCPT ); Sun, 13 Jan 2013 14:55:54 -0500 From: "Rafael J. Wysocki" To: Jiang Liu Cc: Yinghai Lu , Bjorn Helgaas , Len Brown , Taku Izumi , Jiang Liu , linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org, linux-acpi@vger.kernel.org Subject: Re: [PATCH v8 21/22] PCI: add match_driver in struct pci_dev Date: Sun, 13 Jan 2013 21:01:43 +0100 Message-ID: <3209648.ahKUqpvYlm@vostro.rjw.lan> User-Agent: KMail/4.9.5 (Linux/3.8.0-rc3+; KDE/4.9.5; x86_64; ; ) In-Reply-To: <50F2D55C.4040807@gmail.com> References: <1357944049-29620-1-git-send-email-yinghai@kernel.org> <29539918.9ng60fkCeb@vostro.rjw.lan> <50F2D55C.4040807@gmail.com> MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="utf-8" Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sunday, January 13, 2013 11:40:12 PM Jiang Liu wrote: > On 01/13/2013 07:49 AM, Rafael J. Wysocki wrote: > > On Friday, January 11, 2013 02:40:48 PM Yinghai Lu wrote: > >> with that we could move out attaching driver for pci device, > >> out of device_add for pci hot add path. > >> > >> pci_bus_attach_device() will attach driver to pci device. > > > > Clever, but I wonder why exactly we need to do that? > Hi Rafael, > To make following sequence possible, > 1) Create PCI device objects for hot-added PCI host bridge > 2) Create IOMMU devices for DMAR units belong to the hot-added PCI host bridge > 3) Bind and start all PCI devices connected to the PCI host bridge. OK, but why exactly isn't it possible without that change? Rafael > >> Signed-off-by: Yinghai Lu > >> --- > >> drivers/pci/bus.c | 10 ++++++++++ > >> drivers/pci/pci-driver.c | 6 +++++- > >> include/linux/pci.h | 1 + > >> 3 files changed, 16 insertions(+), 1 deletion(-) > >> > >> diff --git a/drivers/pci/bus.c b/drivers/pci/bus.c > >> index 5f9c728..1f5916a 100644 > >> --- a/drivers/pci/bus.c > >> +++ b/drivers/pci/bus.c > >> @@ -160,6 +160,15 @@ pci_bus_alloc_resource(struct pci_bus *bus, struct resource *res, > >> > >> void __weak pcibios_resource_survey_bus(struct pci_bus *bus) { } > >> > >> +static void pci_bus_attach_device(struct pci_dev *dev) > >> +{ > >> + int ret; > >> + > >> + dev->match_driver = true; > >> + ret = device_attach(&dev->dev); > >> + WARN_ON(ret < 0); > >> +} > >> + > >> /** > >> * pci_bus_add_device - add a single device > >> * @dev: device to add > >> @@ -181,6 +190,7 @@ int pci_bus_add_device(struct pci_dev *dev) > >> if (retval) > >> return retval; > >> > >> + pci_bus_attach_device(dev); > >> dev->is_added = 1; > >> pci_proc_attach_device(dev); > >> pci_create_sysfs_dev_files(dev); > >> diff --git a/drivers/pci/pci-driver.c b/drivers/pci/pci-driver.c > >> index f79cbcd..acdcc3c 100644 > >> --- a/drivers/pci/pci-driver.c > >> +++ b/drivers/pci/pci-driver.c > >> @@ -1186,9 +1186,13 @@ pci_dev_driver(const struct pci_dev *dev) > >> static int pci_bus_match(struct device *dev, struct device_driver *drv) > >> { > >> struct pci_dev *pci_dev = to_pci_dev(dev); > >> - struct pci_driver *pci_drv = to_pci_driver(drv); > >> + struct pci_driver *pci_drv; > >> const struct pci_device_id *found_id; > >> > >> + if (!pci_dev->match_driver) > >> + return 0; > >> + > >> + pci_drv = to_pci_driver(drv); > >> found_id = pci_match_device(pci_drv, pci_dev); > >> if (found_id) > >> return 1; > >> diff --git a/include/linux/pci.h b/include/linux/pci.h > >> index 907b455..d73af08 100644 > >> --- a/include/linux/pci.h > >> +++ b/include/linux/pci.h > >> @@ -286,6 +286,7 @@ struct pci_dev { > >> unsigned int irq; > >> struct resource resource[DEVICE_COUNT_RESOURCE]; /* I/O and memory regions + expansion ROMs */ > >> > >> + bool match_driver; > >> /* These fields are used by common fixups */ > >> unsigned int transparent:1; /* Transparent PCI bridge */ > >> unsigned int multifunction:1;/* Part of multi-function device */ > >> > -- I speak only for myself. Rafael J. Wysocki, Intel Open Source Technology Center.