Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751783AbaBJIAG (ORCPT ); Mon, 10 Feb 2014 03:00:06 -0500 Received: from szxga03-in.huawei.com ([119.145.14.66]:48187 "EHLO szxga03-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751371AbaBJIAE (ORCPT ); Mon, 10 Feb 2014 03:00:04 -0500 Message-ID: <52F886ED.7040603@huawei.com> Date: Mon, 10 Feb 2014 15:59:41 +0800 From: Yijing Wang User-Agent: Mozilla/5.0 (Windows NT 6.1; rv:24.0) Gecko/20100101 Thunderbird/24.0.1 MIME-Version: 1.0 To: Oliver Neukum CC: Bjorn Helgaas , , , Hanjun Guo Subject: Re: [PATCH part1 v5 5/7] PCI: Add pci_dummy_ops to isolate pci device temporarily References: <1392005051-54508-1-git-send-email-wangyijing@huawei.com> <1392005051-54508-6-git-send-email-wangyijing@huawei.com> <1392015399.21271.9.camel@linux-fkkt.site> In-Reply-To: <1392015399.21271.9.camel@linux-fkkt.site> Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit X-Originating-IP: [10.177.27.212] X-CFilter-Loop: Reflected Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Oliver, Thanks for your review and comments! >> +static DEFINE_SPINLOCK(pci_freeze_lock); > > The lock is used only here. Also be used in pci_bus_unfreeze_device(); > >> +/** >> + * pci_bus_freeze_device - freeze pci bus to access pci device >> + * @bus: the pci bus to freeze >> + * >> + * Replace pci bus ops by pci_dummy_ops, protect system from >> + * accessing pci devices. >> + */ >> +void pci_bus_freeze_device(struct pci_bus *bus) >> +{ >> + struct pci_ops *ops; >> + unsigned long flags; >> + >> + spin_lock_irqsave(&pci_freeze_lock, flags); >> + ops = pci_bus_set_ops(bus, &pci_dummy_ops); >> + bus->save_ops = ops; >> + spin_unlock_irqrestore(&pci_freeze_lock, flags); > > Against what exactly are you locking here? I want to use this spin lock to serialize freeze device and unfreeze device. Thanks! Yijing. > > > > -- Thanks! Yijing -- 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/