From patchwork Thu Oct 25 01:36:03 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Huang, Ying" X-Patchwork-Id: 194014 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id A0BB92C00A4 for ; Thu, 25 Oct 2012 12:36:16 +1100 (EST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758890Ab2JYBgP (ORCPT ); Wed, 24 Oct 2012 21:36:15 -0400 Received: from mga01.intel.com ([192.55.52.88]:3744 "EHLO mga01.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751243Ab2JYBgO (ORCPT ); Wed, 24 Oct 2012 21:36:14 -0400 Received: from fmsmga001.fm.intel.com ([10.253.24.23]) by fmsmga101.fm.intel.com with ESMTP; 24 Oct 2012 18:36:13 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.80,643,1344236400"; d="scan'208";a="238066027" Received: from yhuang-dev.sh.intel.com ([10.239.13.178]) by fmsmga001.fm.intel.com with ESMTP; 24 Oct 2012 18:36:08 -0700 From: Huang Ying To: Bjorn Helgaas Cc: linux-kernel@vger.kernel.org, linux-pci@vger.kernel.org, linux-pm@vger.kernel.org, "Rafael J. Wysocki" , Huang Ying , stable@vger.kernel.org Subject: [BUGFIX] PCI/PM: Fix proc config reg access for D3cold and bridge suspending Date: Thu, 25 Oct 2012 09:36:03 +0800 Message-Id: <1351128963-10347-1-git-send-email-ying.huang@intel.com> X-Mailer: git-send-email 1.7.10.4 Sender: linux-pci-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org In https://bugzilla.kernel.org/show_bug.cgi?id=48981 Peter reported that /proc/bus/pci/??/??.? does not works for 3.6. This is This is because the device configuration space registers will be not accessible if the corresponding parent bridge is suspended or the device is put into D3cold state. This is the same as /sys/bus/pci/devices/0000:??:??.?/config access issue. So the function used to solve sysfs issue is used to solve this issue. Cc: stable@vger.kernel.org Reported-by: Peter Signed-off-by: Huang Ying Acked-by: Rafael J. Wysocki --- drivers/pci/pci-sysfs.c | 34 ---------------------------------- drivers/pci/pci.c | 32 ++++++++++++++++++++++++++++++++ drivers/pci/pci.h | 2 ++ drivers/pci/proc.c | 8 ++++++++ 4 files changed, 42 insertions(+), 34 deletions(-) -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html --- a/drivers/pci/pci-sysfs.c +++ b/drivers/pci/pci-sysfs.c @@ -458,40 +458,6 @@ boot_vga_show(struct device *dev, struct } struct device_attribute vga_attr = __ATTR_RO(boot_vga); -static void -pci_config_pm_runtime_get(struct pci_dev *pdev) -{ - struct device *dev = &pdev->dev; - struct device *parent = dev->parent; - - if (parent) - pm_runtime_get_sync(parent); - pm_runtime_get_noresume(dev); - /* - * pdev->current_state is set to PCI_D3cold during suspending, - * so wait until suspending completes - */ - pm_runtime_barrier(dev); - /* - * Only need to resume devices in D3cold, because config - * registers are still accessible for devices suspended but - * not in D3cold. - */ - if (pdev->current_state == PCI_D3cold) - pm_runtime_resume(dev); -} - -static void -pci_config_pm_runtime_put(struct pci_dev *pdev) -{ - struct device *dev = &pdev->dev; - struct device *parent = dev->parent; - - pm_runtime_put(dev); - if (parent) - pm_runtime_put_sync(parent); -} - static ssize_t pci_read_config(struct file *filp, struct kobject *kobj, struct bin_attribute *bin_attr, --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -1858,6 +1858,38 @@ bool pci_dev_run_wake(struct pci_dev *de } EXPORT_SYMBOL_GPL(pci_dev_run_wake); +void pci_config_pm_runtime_get(struct pci_dev *pdev) +{ + struct device *dev = &pdev->dev; + struct device *parent = dev->parent; + + if (parent) + pm_runtime_get_sync(parent); + pm_runtime_get_noresume(dev); + /* + * pdev->current_state is set to PCI_D3cold during suspending, + * so wait until suspending completes + */ + pm_runtime_barrier(dev); + /* + * Only need to resume devices in D3cold, because config + * registers are still accessible for devices suspended but + * not in D3cold. + */ + if (pdev->current_state == PCI_D3cold) + pm_runtime_resume(dev); +} + +void pci_config_pm_runtime_put(struct pci_dev *pdev) +{ + struct device *dev = &pdev->dev; + struct device *parent = dev->parent; + + pm_runtime_put(dev); + if (parent) + pm_runtime_put_sync(parent); +} + /** * pci_pm_init - Initialize PM functions of given PCI device * @dev: PCI device to handle. --- a/drivers/pci/pci.h +++ b/drivers/pci/pci.h @@ -72,6 +72,8 @@ extern void pci_disable_enabled_device(s extern int pci_finish_runtime_suspend(struct pci_dev *dev); extern int __pci_pme_wakeup(struct pci_dev *dev, void *ign); extern void pci_wakeup_bus(struct pci_bus *bus); +extern void pci_config_pm_runtime_get(struct pci_dev *dev); +extern void pci_config_pm_runtime_put(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); --- a/drivers/pci/proc.c +++ b/drivers/pci/proc.c @@ -76,6 +76,8 @@ proc_bus_pci_read(struct file *file, cha if (!access_ok(VERIFY_WRITE, buf, cnt)) return -EINVAL; + pci_config_pm_runtime_get(dev); + if ((pos & 1) && cnt) { unsigned char val; pci_user_read_config_byte(dev, pos, &val); @@ -121,6 +123,8 @@ proc_bus_pci_read(struct file *file, cha cnt--; } + pci_config_pm_runtime_put(dev); + *ppos = pos; return nbytes; } @@ -146,6 +150,8 @@ proc_bus_pci_write(struct file *file, co if (!access_ok(VERIFY_READ, buf, cnt)) return -EINVAL; + pci_config_pm_runtime_get(dev); + if ((pos & 1) && cnt) { unsigned char val; __get_user(val, buf); @@ -191,6 +197,8 @@ proc_bus_pci_write(struct file *file, co cnt--; } + pci_config_pm_runtime_put(dev); + *ppos = pos; i_size_write(ino, dp->size); return nbytes;