From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Rafael J. Wysocki" Subject: [PATCH v3 2/3] PM / PCI / ACPI: Kick devices that might have been reset by firmware Date: Wed, 07 Oct 2015 00:50:24 +0200 Message-ID: <1973640.XGUdor7p6A@vostro.rjw.lan> References: <10641052.oOBhM6BU9G@vostro.rjw.lan> <5472042.4c1h9diL7E@vostro.rjw.lan> <2723857.EVg1dAvTli@vostro.rjw.lan> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7Bit Return-path: In-Reply-To: <2723857.EVg1dAvTli@vostro.rjw.lan> Sender: linux-kernel-owner@vger.kernel.org To: Linux PM list Cc: Linux Kernel Mailing List , ACPI Devel Maling List , Alan Stern , Dmitry Torokhov , Daniel Vetter , Bjorn Helgaas , Linux PCI List-Id: linux-acpi@vger.kernel.org From: Rafael J. Wysocki There is a concern that if the platform firmware was involved in the system resume that's being completed, some devices might have been reset by it and if those devices had the power.direct_complete flag set during the preceding suspend transition, they may stay in a reset-power-on state indefinitely (until they are runtime-resumed and then suspended again). That may not be a big deal from the individual device's perspective, but if the system is an SoC, it may be prevented from entering deep SoC-wide low-power states on idle because of that. The devices that are most likely to be affected by this issue are PCI devices and ACPI-enumerated devices using the general ACPI PM domain, so to prevent it from happening for those devices, force a runtime resume for them if they have their power.direct_complete flags set and the platform firmware was involved in the resume transition currently in progress. Signed-off-by: Rafael J. Wysocki --- drivers/acpi/acpi_lpss.c | 2 +- drivers/acpi/device_pm.c | 19 +------------------ drivers/base/power/generic_ops.c | 23 +++++++++++++++++++++++ drivers/pci/pci-driver.c | 2 +- include/linux/pm.h | 2 +- 5 files changed, 27 insertions(+), 21 deletions(-) Index: linux-pm/drivers/acpi/device_pm.c =================================================================== --- linux-pm.orig/drivers/acpi/device_pm.c +++ linux-pm/drivers/acpi/device_pm.c @@ -963,23 +963,6 @@ int acpi_subsys_prepare(struct device *d EXPORT_SYMBOL_GPL(acpi_subsys_prepare); /** - * acpi_subsys_complete - Finalize device's resume during system resume. - * @dev: Device to handle. - */ -void acpi_subsys_complete(struct device *dev) -{ - pm_generic_complete(dev); - /* - * If the device had been runtime-suspended before the system went into - * the sleep state it is going out of and it has never been resumed till - * now, resume it in case the firmware powered it up. - */ - if (dev->power.direct_complete) - pm_request_resume(dev); -} -EXPORT_SYMBOL_GPL(acpi_subsys_complete); - -/** * acpi_subsys_suspend - Run the device driver's suspend callback. * @dev: Device to handle. * @@ -1047,7 +1030,7 @@ static struct dev_pm_domain acpi_general .runtime_resume = acpi_subsys_runtime_resume, #ifdef CONFIG_PM_SLEEP .prepare = acpi_subsys_prepare, - .complete = acpi_subsys_complete, + .complete = pm_complete_with_resume_check, .suspend = acpi_subsys_suspend, .suspend_late = acpi_subsys_suspend_late, .resume_early = acpi_subsys_resume_early, Index: linux-pm/drivers/acpi/acpi_lpss.c =================================================================== --- linux-pm.orig/drivers/acpi/acpi_lpss.c +++ linux-pm/drivers/acpi/acpi_lpss.c @@ -664,7 +664,7 @@ static struct dev_pm_domain acpi_lpss_pm #ifdef CONFIG_PM #ifdef CONFIG_PM_SLEEP .prepare = acpi_subsys_prepare, - .complete = acpi_subsys_complete, + .complete = pm_complete_with_resume_check, .suspend = acpi_subsys_suspend, .suspend_late = acpi_lpss_suspend_late, .resume_early = acpi_lpss_resume_early, Index: linux-pm/drivers/base/power/generic_ops.c =================================================================== --- linux-pm.orig/drivers/base/power/generic_ops.c +++ linux-pm/drivers/base/power/generic_ops.c @@ -9,6 +9,7 @@ #include #include #include +#include #ifdef CONFIG_PM /** @@ -297,4 +298,26 @@ void pm_generic_complete(struct device * if (drv && drv->pm && drv->pm->complete) drv->pm->complete(dev); } + +/** + * pm_complete_with_resume_check - Complete a device power transition. + * @dev: Device to handle. + * + * Complete a device power transition during a system-wide power transition and + * optionally schedule a runtime resume of the device if the system resume in + * progress has been initated by the platform firmware and the device had its + * power.direct_complete flag set. + */ +void pm_complete_with_resume_check(struct device *dev) +{ + pm_generic_complete(dev); + /* + * If the device had been runtime-suspended before the system went into + * the sleep state it is going out of and it has never been resumed till + * now, resume it in case the firmware powered it up. + */ + if (dev->power.direct_complete && pm_resume_via_firmware()) + pm_request_resume(dev); +} +EXPORT_SYMBOL_GPL(pm_complete_with_resume_check); #endif /* CONFIG_PM_SLEEP */ Index: linux-pm/drivers/pci/pci-driver.c =================================================================== --- linux-pm.orig/drivers/pci/pci-driver.c +++ linux-pm/drivers/pci/pci-driver.c @@ -687,7 +687,7 @@ static int pci_pm_prepare(struct device static void pci_pm_complete(struct device *dev) { pci_dev_complete_resume(to_pci_dev(dev)); - pm_generic_complete(dev); + pm_complete_with_resume_check(dev); } #else /* !CONFIG_PM_SLEEP */ Index: linux-pm/include/linux/pm.h =================================================================== --- linux-pm.orig/include/linux/pm.h +++ linux-pm/include/linux/pm.h @@ -731,7 +731,7 @@ extern int pm_generic_restore(struct dev extern int pm_generic_poweroff_noirq(struct device *dev); extern int pm_generic_poweroff_late(struct device *dev); extern int pm_generic_poweroff(struct device *dev); -extern void pm_generic_complete(struct device *dev); +extern void pm_complete_with_resume_check(struct device *dev); #else /* !CONFIG_PM_SLEEP */