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authorRafael J. Wysocki <rafael.j.wysocki@intel.com>2016-10-30 17:32:31 +0100
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2016-10-31 11:42:51 -0600
commit21d5c57b3726166421251e94dabab047baaf8ce4 (patch)
tree11534c3ef07222913f2527c9c8ff41478d259777 /drivers/base/dd.c
parent8c73b4288496407d91bc616df3f7c62a88356cb2 (diff)
downloadlinux-21d5c57b3726166421251e94dabab047baaf8ce4.tar.bz2
PM / runtime: Use device links
Modify the runtime PM framework to use device links to ensure that supplier devices will not be suspended if any of their consumer devices are active. The idea is to reference count suppliers on the consumer's resume and drop references to them on its suspend. The information on whether or not the supplier has been reference counted by the consumer's (runtime) resume is stored in a new field (rpm_active) in the link object for each link. It may be necessary to clean up those references when the supplier is unbinding and that's why the links whose status is DEVICE_LINK_SUPPLIER_UNBIND are skipped by the runtime suspend and resume code. The above means that if the consumer device is probed in the runtime-active state, the supplier has to be resumed and reference counted by device_link_add() so the code works as expected on its (runtime) suspend. There is a new flag, DEVICE_LINK_RPM_ACTIVE, to tell device_link_add() about that (in which case the caller is responsible for making sure that the consumer really will be runtime-active when runtime PM is enabled for it). The other new link flag, DEVICE_LINK_PM_RUNTIME, tells the core whether or not the link should be used for runtime PM at all. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/base/dd.c')
-rw-r--r--drivers/base/dd.c3
1 files changed, 3 insertions, 0 deletions
diff --git a/drivers/base/dd.c b/drivers/base/dd.c
index b2bca3cf0dd2..43be1cc751a4 100644
--- a/drivers/base/dd.c
+++ b/drivers/base/dd.c
@@ -513,6 +513,7 @@ int driver_probe_device(struct device_driver *drv, struct device *dev)
pr_debug("bus: '%s': %s: matched device %s with driver %s\n",
drv->bus->name, __func__, dev_name(dev), drv->name);
+ pm_runtime_get_suppliers(dev);
if (dev->parent)
pm_runtime_get_sync(dev->parent);
@@ -523,6 +524,7 @@ int driver_probe_device(struct device_driver *drv, struct device *dev)
if (dev->parent)
pm_runtime_put(dev->parent);
+ pm_runtime_put_suppliers(dev);
return ret;
}
@@ -806,6 +808,7 @@ static void __device_release_driver(struct device *dev, struct device *parent)
}
pm_runtime_get_sync(dev);
+ pm_runtime_clean_up_links(dev);
driver_sysfs_remove(dev);