Commit 58a1fbbb authored by Rafael J. Wysocki's avatar Rafael J. Wysocki
Browse files

PM / PCI / ACPI: Kick devices that might have been reset by firmware 



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: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
parent ef25ba04

drivers/acpi/acpi_lpss.c

+1 −1
Original line number Diff line number Diff line
@@ -664,7 +664,7 @@ static struct dev_pm_domain acpi_lpss_pm_domain = { 
#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,

drivers/acpi/device_pm.c

+1 −18
Original line number Diff line number Diff line
@@ -962,23 +962,6 @@ int acpi_subsys_prepare(struct device *dev) 
}

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_pm_domain = { 
		.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,

drivers/base/power/generic_ops.c

+23 −0
Original line number Diff line number Diff line
@@ -9,6 +9,7 @@ 
#include <linux/pm.h>

#include <linux/pm_runtime.h>

#include <linux/export.h>

#include <linux/suspend.h>



#ifdef CONFIG_PM

/**
@@ -297,4 +298,26 @@ void pm_generic_complete(struct device *dev) 
	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 */

drivers/pci/pci-driver.c

+1 −1
Original line number Diff line number Diff line
@@ -687,7 +687,7 @@ static int pci_pm_prepare(struct device *dev) 
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 */

include/linux/pm.h

+1 −0
Original line number Diff line number Diff line
@@ -732,6 +732,7 @@ 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 */

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