Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755061Ab3EHTOo (ORCPT ); Wed, 8 May 2013 15:14:44 -0400 Received: from mx1.redhat.com ([209.132.183.28]:15112 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753251Ab3EHTOm (ORCPT ); Wed, 8 May 2013 15:14:42 -0400 Message-ID: <518AA420.5020900@redhat.com> Date: Wed, 08 May 2013 15:14:40 -0400 From: Don Dutile User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:10.0.11) Gecko/20121116 Thunderbird/10.0.11 MIME-Version: 1.0 To: Alex Williamson CC: bhelgaas@google.com, linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v2 1/8] pci: Create pci_reset_bridge_secondary_bus() References: <20130508025339.30771.61937.stgit@bling.home> <20130508025740.30771.50033.stgit@bling.home> In-Reply-To: <20130508025740.30771.50033.stgit@bling.home> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3688 Lines: 96 On 05/07/2013 10:57 PM, Alex Williamson wrote: > Move the secondary bus reset code from pci_parent_bus_reset() into its own > function. Export it as we'll later be calling it from hotplug controllers. > > Signed-off-by: Alex Williamson > --- > drivers/pci/pci.c | 32 +++++++++++++++++++++++--------- > include/linux/pci.h | 1 + > 2 files changed, 24 insertions(+), 9 deletions(-) > > diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c > index b099e00..d0f313f 100644 > --- a/drivers/pci/pci.c > +++ b/drivers/pci/pci.c > @@ -3210,9 +3210,30 @@ static int pci_pm_reset(struct pci_dev *dev, int probe) > return 0; > } > > -static int pci_parent_bus_reset(struct pci_dev *dev, int probe) > +/** > + * pci_reset_bridge_secondary_bus - Reset the secondary bus on a PCI bridge. > + * @dev: Bridge device > + * > + * Use the bridge control register to assert reset on the secondary bus. > + * Devices on the secondary bus are left in power-on state. > + */ > +void pci_reset_bridge_secondary_bus(struct pci_dev *dev) see recommended api change below... > { > u16 ctrl; > + > + pci_read_config_word(dev, PCI_BRIDGE_CONTROL,&ctrl); > + ctrl |= PCI_BRIDGE_CTL_BUS_RESET; > + pci_write_config_word(dev, PCI_BRIDGE_CONTROL, ctrl); > + msleep(100); > + > + ctrl&= ~PCI_BRIDGE_CTL_BUS_RESET; > + pci_write_config_word(dev, PCI_BRIDGE_CONTROL, ctrl); > + msleep(100); > +} > +EXPORT_SYMBOL_GPL(pci_reset_bridge_secondary_bus); > + > +static int pci_parent_bus_reset(struct pci_dev *dev, int probe) > +{ > struct pci_dev *pdev; > > if (pci_is_root_bus(dev->bus) || dev->subordinate || !dev->bus->self) > @@ -3225,14 +3246,7 @@ static int pci_parent_bus_reset(struct pci_dev *dev, int probe) > if (probe) > return 0; > > - pci_read_config_word(dev->bus->self, PCI_BRIDGE_CONTROL,&ctrl); > - ctrl |= PCI_BRIDGE_CTL_BUS_RESET; > - pci_write_config_word(dev->bus->self, PCI_BRIDGE_CONTROL, ctrl); > - msleep(100); > - > - ctrl&= ~PCI_BRIDGE_CTL_BUS_RESET; > - pci_write_config_word(dev->bus->self, PCI_BRIDGE_CONTROL, ctrl); > - msleep(100); > + pci_reset_bridge_secondary_bus(dev->bus->self); > It makes more sense to pass the pci-bus struct of the bus you want to reset, instead of the pdev of the bridge that bus is sourced by. i.e, dev->bus, and above, extract the pdev from the bus-struct. That way, devices asking for bus-reset, don't have to know the bus-struct details to make the call right... just their own pdev->bus reference. (more object-like/clean). > return 0; > } > diff --git a/include/linux/pci.h b/include/linux/pci.h > index 710067f..695620c 100644 > --- a/include/linux/pci.h > +++ b/include/linux/pci.h > @@ -905,6 +905,7 @@ int pcie_set_mps(struct pci_dev *dev, int mps); > int __pci_reset_function(struct pci_dev *dev); > int __pci_reset_function_locked(struct pci_dev *dev); > int pci_reset_function(struct pci_dev *dev); > +void pci_reset_bridge_secondary_bus(struct pci_dev *dev); and final tweak. > void pci_update_resource(struct pci_dev *dev, int resno); > int __must_check pci_assign_resource(struct pci_dev *dev, int i); > int __must_check pci_reassign_resource(struct pci_dev *dev, int i, resource_size_t add_size, resource_size_t align); > > -- > To unsubscribe from this list: send the line "unsubscribe linux-pci" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html -- 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/