From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from ogre.sisk.pl ([193.178.161.156]:44134 "EHLO ogre.sisk.pl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932554Ab2F1Jzf (ORCPT ); Thu, 28 Jun 2012 05:55:35 -0400 From: "Rafael J. Wysocki" To: Bjorn Helgaas Subject: [PATCH] PCI / PM: Restore the original behavior of pci_set_power_state() Date: Thu, 28 Jun 2012 12:01:02 +0200 Cc: Jesse Barnes , Linux PM mailing list , LKML , Matthew Garrett , "linux-pci" MIME-Version: 1.0 Content-Type: Text/Plain; charset="utf-8" Message-Id: <201206281201.02414.rjw@sisk.pl> Sender: linux-pci-owner@vger.kernel.org List-ID: From: Rafael J. Wysocki Commit cc2893b6 (PCI: Ensure we re-enable devices on resume) addressed the problem with USB not being powered after resume on recent Lenovo machines, but it did that in a suboptimal way. Namely, it should have changed the relevant code paths only, which are pci_pm_resume_noirq() and pci_pm_restore_noirq() supposed to restore the device's power and standard configuration registers after system resume from suspend or hibernation. Instead, however, it modified pci_set_power_state() which is executed in several other situations too. That resulted in some undesirable effects, like attempting to change a device's power state in the same way multiple times in a row (up to as many as 4 times in a row in the snd_hda_intel driver). Fix the bug addressed by commit cc2893b6 in an alternative way, by forcibly powering up all devices in pci_pm_default_resume_early(), which is called by pci_pm_resume_noirq() and pci_pm_restore_noirq() to restore the device's power and standard configuration registers, and modifying pci_pm_runtime_resume() to avoid the forcible power-up if not necessary. Then, revert the changes made by commit cc2893b6 to make the confusion introduced by it go away. Signed-off-by: Rafael J. Wysocki --- drivers/pci/pci-driver.c | 14 ++++++++------ drivers/pci/pci.c | 19 ++++++++++++++++++- drivers/pci/pci.h | 1 + 3 files changed, 27 insertions(+), 7 deletions(-) Index: linux/drivers/pci/pci.c =================================================================== --- linux.orig/drivers/pci/pci.c +++ linux/drivers/pci/pci.c @@ -662,6 +662,19 @@ void pci_update_current_state(struct pci } /** + * pci_power_up - Put the given device into D0 forcibly + * @dev: PCI device to power up + */ +void pci_power_up(struct pci_dev *dev) +{ + if (platform_pci_power_manageable(dev)) + platform_pci_set_power_state(dev, PCI_D0); + + pci_raw_set_power_state(dev, PCI_D0); + pci_update_current_state(dev, PCI_D0); +} + +/** * pci_platform_power_transition - Use platform to change device power state * @dev: PCI device to handle. * @state: State to put the device into. @@ -707,7 +720,7 @@ static void __pci_start_power_transition */ int __pci_complete_power_transition(struct pci_dev *dev, pci_power_t state) { - return state >= PCI_D0 ? + return state > PCI_D0 ? pci_platform_power_transition(dev, state) : -EINVAL; } EXPORT_SYMBOL_GPL(__pci_complete_power_transition); @@ -744,6 +757,10 @@ int pci_set_power_state(struct pci_dev * */ return 0; + /* Check if we're already there */ + if (dev->current_state == state) + return 0; + __pci_start_power_transition(dev, state); /* This device is quirked not to be put into D3, so Index: linux/drivers/pci/pci-driver.c =================================================================== --- linux.orig/drivers/pci/pci-driver.c +++ linux/drivers/pci/pci-driver.c @@ -459,16 +459,17 @@ static int pci_restore_standard_config(s return 0; } +#endif + +#ifdef CONFIG_PM_SLEEP + static void pci_pm_default_resume_early(struct pci_dev *pci_dev) { - pci_restore_standard_config(pci_dev); + pci_power_up(pci_dev); + pci_restore_state(pci_dev); pci_fixup_device(pci_fixup_resume_early, pci_dev); } -#endif - -#ifdef CONFIG_PM_SLEEP - /* * Default "suspend" method for devices that have no driver provided suspend, * or not even a driver at all (second part). @@ -1050,7 +1051,8 @@ static int pci_pm_runtime_resume(struct if (!pm || !pm->runtime_resume) return -ENOSYS; - pci_pm_default_resume_early(pci_dev); + pci_restore_standard_config(pci_dev); + pci_fixup_device(pci_fixup_resume_early, pci_dev); __pci_enable_wake(pci_dev, PCI_D0, true, false); pci_fixup_device(pci_fixup_resume, pci_dev); Index: linux/drivers/pci/pci.h =================================================================== --- linux.orig/drivers/pci/pci.h +++ linux/drivers/pci/pci.h @@ -67,6 +67,7 @@ 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_power_up(struct pci_dev *dev); extern void pci_disable_enabled_device(struct pci_dev *dev); extern int pci_finish_runtime_suspend(struct pci_dev *dev); extern int __pci_pme_wakeup(struct pci_dev *dev, void *ign);