diff options
Diffstat (limited to 'drivers/base/power/runtime.c')
| -rw-r--r-- | drivers/base/power/runtime.c | 35 |
1 files changed, 30 insertions, 5 deletions
diff --git a/drivers/base/power/runtime.c b/drivers/base/power/runtime.c index 60ebb04d8140..f0d863089345 100644 --- a/drivers/base/power/runtime.c +++ b/drivers/base/power/runtime.c @@ -1489,6 +1489,16 @@ int pm_runtime_force_suspend(struct device *dev) if (ret) goto err; + /* + * Increase the runtime PM usage count for the device's parent, in case + * when we find the device being used when system suspend was invoked. + * This informs pm_runtime_force_resume() to resume the parent + * immediately, which is needed to be able to resume its children, + * when not deferring the resume to be managed via runtime PM. + */ + if (dev->parent && atomic_read(&dev->power.usage_count) > 1) + pm_runtime_get_noresume(dev->parent); + pm_runtime_set_suspended(dev); return 0; err: @@ -1498,16 +1508,20 @@ err: EXPORT_SYMBOL_GPL(pm_runtime_force_suspend); /** - * pm_runtime_force_resume - Force a device into resume state. + * pm_runtime_force_resume - Force a device into resume state if needed. * @dev: Device to resume. * * Prior invoking this function we expect the user to have brought the device * into low power state by a call to pm_runtime_force_suspend(). Here we reverse - * those actions and brings the device into full power. We update the runtime PM - * status and re-enables runtime PM. + * those actions and brings the device into full power, if it is expected to be + * used on system resume. To distinguish that, we check whether the runtime PM + * usage count is greater than 1 (the PM core increases the usage count in the + * system PM prepare phase), as that indicates a real user (such as a subsystem, + * driver, userspace, etc.) is using it. If that is the case, the device is + * expected to be used on system resume as well, so then we resume it. In the + * other case, we defer the resume to be managed via runtime PM. * - * Typically this function may be invoked from a system resume callback to make - * sure the device is put into full power state. + * Typically this function may be invoked from a system resume callback. */ int pm_runtime_force_resume(struct device *dev) { @@ -1524,6 +1538,17 @@ int pm_runtime_force_resume(struct device *dev) if (!pm_runtime_status_suspended(dev)) goto out; + /* + * Decrease the parent's runtime PM usage count, if we increased it + * during system suspend in pm_runtime_force_suspend(). + */ + if (atomic_read(&dev->power.usage_count) > 1) { + if (dev->parent) + pm_runtime_put_noidle(dev->parent); + } else { + goto out; + } + ret = pm_runtime_set_active(dev); if (ret) goto out; |