From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Xudong Hao To: bhelgaas@google.com Cc: linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org, kvm@vger.kernel.org, avi@redhat.com, alex.williamson@redhat.com, ddutile@redhat.com, myron.stowe@redhat.com, xiantao.zhang@intel.com, xudong.hao@intel.com Subject: [PATCH 3/4] Enable OBFF before device is used by driver Date: Fri, 8 Jun 2012 16:01:31 +0800 Message-Id: <1339142492-13625-4-git-send-email-xudong.hao@intel.com> In-Reply-To: <1339142492-13625-1-git-send-email-xudong.hao@intel.com> References: <1339142492-13625-1-git-send-email-xudong.hao@intel.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: Enable OBFF(optimized buffer flush/fill) in pci_enable_device() function, make sure this feature is enabled before device is used by driver. Signed-off-by: Xudong Hao --- drivers/pci/pci.c | 9 +++++++++ 1 files changed, 9 insertions(+), 0 deletions(-) diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index 5e5e3ad..35127c1 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -1144,11 +1144,20 @@ static void pci_enable_dev_caps(struct pci_dev *dev) * tolerance for snooped & unsnooped memory transactions. */ pci_enable_ltr(dev); + + /* + * OBFF (optimized buffer flush/fill), where supported, + * can help improve energy efficiency by giving devices + * information about when interrupts and other activity + * will have a reduced power impact. + */ + pci_enable_obff(dev, PCI_EXP_OBFF_SIGNAL_L0); } static void pci_disable_dev_caps(struct pci_dev *dev) { pci_disable_ltr(dev); + pci_disable_obff(dev); } static int do_pci_enable_device(struct pci_dev *dev, int bars) -- 1.5.5