diff options
| author | Rafael J. Wysocki | 2015-10-07 00:50:24 +0200 |
|---|---|---|
| committer | Rafael J. Wysocki | 2015-10-14 02:17:34 +0200 |
| commit | 58a1fbbb2ee873dd1fe327e80bc7b08e80866269 (patch) | |
| tree | 3c3552e6631af82c4afb3f449ae8042bc925bf53 /drivers/base | |
| parent | ef25ba0476015908ef5960f9faac149ddf34ede0 (diff) | |
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: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Diffstat (limited to 'drivers/base')
| -rw-r--r-- | drivers/base/power/generic_ops.c | 23 |
1 files changed, 23 insertions, 0 deletions
diff --git a/drivers/base/power/generic_ops.c b/drivers/base/power/generic_ops.c index b2ed606265a8..07c3c4a9522d 100644 --- a/drivers/base/power/generic_ops.c +++ b/drivers/base/power/generic_ops.c @@ -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 */ |