Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754262Ab2ENCoy (ORCPT ); Sun, 13 May 2012 22:44:54 -0400 Received: from mga01.intel.com ([192.55.52.88]:53148 "EHLO mga01.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753978Ab2ENCow (ORCPT ); Sun, 13 May 2012 22:44:52 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.71,315,1320652800"; d="scan'208";a="165771124" Date: Mon, 14 May 2012 10:48:16 +0800 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, xiantao.zhang@intel.com, xudong.hao@intel.com Subject: [PATCH 1/1] Enable LTR/OBFF before device is used by driver Message-ID: <20120514024816.GA15371@hp-xd.sh.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.5.19 (2009-01-05) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2198 Lines: 71 Enable LTR(Latency tolerance reporting) and OBFF(optimized buffer flush/fill) in pci_enable_device(), so that they are enabled before the device is used by driver. Signed-off-by: Xudong Hao --- drivers/pci/pci.c | 29 +++++++++++++++++++++++++++++ 1 files changed, 29 insertions(+), 0 deletions(-) diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index 111569c..2369883 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -1134,6 +1134,31 @@ int pci_load_and_free_saved_state(struct pci_dev *dev, } EXPORT_SYMBOL_GPL(pci_load_and_free_saved_state); +static void pci_enable_dev_caps(struct pci_dev *dev) +{ + /* set default value */ + unsigned long type = PCI_EXP_OBFF_SIGNAL_ALWAYS; + + /* LTR(Latency tolerance reporting) allows devices to send + * messages to the root complex indicating their latency + * 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, type); +} + +static void pci_disable_dev_caps(struct pci_dev *dev) +{ + pci_disable_obff(dev); + pci_disable_ltr(dev); +} + static int do_pci_enable_device(struct pci_dev *dev, int bars) { int err; @@ -1146,6 +1171,9 @@ static int do_pci_enable_device(struct pci_dev *dev, int bars) return err; pci_fixup_device(pci_fixup_enable, dev); + /* Enable some device capibility before it's used by driver. */ + pci_enable_dev_caps(dev); + return 0; } @@ -1361,6 +1389,7 @@ static void do_pci_disable_device(struct pci_dev *dev) } pcibios_disable_device(dev); + pci_disable_dev_caps(dev); } /** -- 1.6.0.rc1 -- 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/