From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sinan Kaya Subject: Re: [PATCH 1/2] PCI: save and restore device state during bus reset Date: Tue, 13 Sep 2016 19:31:18 -0400 Message-ID: References: <1472770801-30671-1-git-send-email-okaya@codeaurora.org> <20160913215315.GJ4138@localhost> <46a47bf2-ab39-0ee2-0faf-2f4050f2a89d@codeaurora.org> Mime-Version: 1.0 Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <46a47bf2-ab39-0ee2-0faf-2f4050f2a89d@codeaurora.org> Sender: linux-pci-owner@vger.kernel.org To: Bjorn Helgaas Cc: linux-pci@vger.kernel.org, timur@codeaurora.org, cov@codeaurora.org, alex.williamson@redhat.com, vikrams@codeaurora.org, linux-arm-msm@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org List-Id: linux-arm-msm@vger.kernel.org On 9/13/2016 7:20 PM, Sinan Kaya wrote: > On 9/13/2016 5:53 PM, Bjorn Helgaas wrote: >>> + pci_bus_restore(dev->bus); >> This path eventually writes the Bridge Control register: >> >> pci_reset_bridge_secondary_bus >> pcibios_reset_secondary_bus >> pci_reset_secondary_bus >> pci_write_config_word(dev, PCI_BRIDGE_CONTROL, ctrl) >> >> But I think it'd be easy to call this on a non-bridge device, and I >> don't think there's anything in the path that checks whether this is >> actually a bridge. I wonder if we should check that somewhere, or >> maybe even change the interface so it takes a struct pci_bus instead >> of a pci_dev. >> > > I'll change it to pci_bus. > >>>> +} > > Changing the API seems to become a bigger mess. pcibios_reset_secondary_bus has weaker friends in different architectures. I can move the check in pci_parent_bus_reset if (pci_is_root_bus(dev->bus) || dev->subordinate || !dev->bus->self || dev->dev_flags & PCI_DEV_FLAGS_NO_BUS_RESET) return -ENOTTY; inside pci_reset_bridge_secondary_bus instead. -- Sinan Kaya Qualcomm Datacenter Technologies, Inc. as an affiliate of Qualcomm Technologies, Inc. Qualcomm Technologies, Inc. is a member of the Code Aurora Forum, a Linux Foundation Collaborative Project.