Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933153AbZJHWzE (ORCPT ); Thu, 8 Oct 2009 18:55:04 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932819AbZJHWyo (ORCPT ); Thu, 8 Oct 2009 18:54:44 -0400 Received: from ogre.sisk.pl ([217.79.144.158]:45254 "EHLO ogre.sisk.pl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932736AbZJHWyk (ORCPT ); Thu, 8 Oct 2009 18:54:40 -0400 From: "Rafael J. Wysocki" To: Linux PCI Subject: [RFC][PATCH 1/4] PCI PM: Add function for checking PME status of devices Date: Fri, 9 Oct 2009 00:52:48 +0200 User-Agent: KMail/1.12.1 (Linux/2.6.32-rc3-rjw; KDE/4.3.1; x86_64; ; ) Cc: pm list , Jesse Barnes , Matthew Garrett , ACPI Devel Maling List , LKML , Alan Stern , Shaohua Li , Bjorn Helgaas References: <200910090051.50932.rjw@sisk.pl> In-Reply-To: <200910090051.50932.rjw@sisk.pl> MIME-Version: 1.0 Content-Type: Text/Plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Message-Id: <200910090052.48493.rjw@sisk.pl> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2693 Lines: 77 From: Rafael J. Wysocki Add function pci_check_pme_status() that will check the PME status bit of given device and clear it along with the PME enable bit. It will be necessary for PCI run-time power management. Based on a patch from Shaohua Li Signed-off-by: Rafael J. Wysocki --- drivers/pci/pci.c | 35 +++++++++++++++++++++++++++++++++++ drivers/pci/pci.h | 1 + 2 files changed, 36 insertions(+) Index: linux-2.6/drivers/pci/pci.h =================================================================== --- linux-2.6.orig/drivers/pci/pci.h +++ linux-2.6/drivers/pci/pci.h @@ -49,6 +49,7 @@ struct pci_platform_pm_ops { extern int pci_set_platform_pm(struct pci_platform_pm_ops *ops); extern void pci_update_current_state(struct pci_dev *dev, pci_power_t state); extern void pci_disable_enabled_device(struct pci_dev *dev); +extern bool pci_check_pme_status(struct pci_dev *dev); extern void pci_pm_init(struct pci_dev *dev); extern void platform_pci_wakeup_init(struct pci_dev *dev); extern void pci_allocate_cap_save_buffers(struct pci_dev *dev); Index: linux-2.6/drivers/pci/pci.c =================================================================== --- linux-2.6.orig/drivers/pci/pci.c +++ linux-2.6/drivers/pci/pci.c @@ -1167,6 +1167,41 @@ int pci_set_pcie_reset_state(struct pci_ } /** + * pci_check_pme_status - Check if given device has generated PME. + * @dev: Device to check. + * + * Check the PME status of the device, clear PME status and PME enable. Return + * 'true' if PME has been generated by the device (and hasn't been spurious) or + * 'false' otherwise. + */ +bool pci_check_pme_status(struct pci_dev *dev) +{ + int pmcsr_pos; + u16 pmcsr; + bool ret = false; + + if (!dev->pm_cap) + return false; + + pmcsr_pos = dev->pm_cap + PCI_PM_CTRL; + /* clear PME status and disable PME to avoid interrupt flood */ + pci_read_config_word(dev, pmcsr_pos, &pmcsr); + if (!(pmcsr & PCI_PM_CTRL_PME_STATUS)) + return false; + + pmcsr |= PCI_PM_CTRL_PME_STATUS; + /* Ignore spurious PME or clear PME enable if it's not spurious. */ + if (pmcsr & PCI_PM_CTRL_PME_ENABLE) { + pmcsr &= ~PCI_PM_CTRL_PME_ENABLE; + ret = true; + } + + pci_write_config_word(dev, pmcsr_pos, pmcsr); + + return ret; +} + +/** * pci_pme_capable - check the capability of PCI device to generate PME# * @dev: PCI device to handle. * @state: PCI state from which device will issue PME#. -- 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/