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authorRafael J. Wysocki <rafael.j.wysocki@intel.com>2017-11-16 22:51:22 +0100
committerRafael J. Wysocki <rafael.j.wysocki@intel.com>2017-11-16 22:51:22 +0100
commitf8817f61e8215b0ff1b73a0d33fa04ef9e6bce8b (patch)
tree6c90b8f2ee96d1a384f96f437e05d4d937a7fdae
parentbd2cd7d5a8f83ddc761025f42a3ca8e56351a6cc (diff)
downloadlinux-stericsson-f8817f61e8215b0ff1b73a0d33fa04ef9e6bce8b.tar.gz
PM / runtime: Drop children check from __pm_runtime_set_status()
The check for "active" children in __pm_runtime_set_status(), when trying to set the parent device status to "suspended", doesn't really make sense, because in fact it is not invalid to set the status of a device with runtime PM disabled to "suspended" in any case. It is invalid to enable runtime PM for a device with its status set to "suspended" while its child_count reference counter is nonzero, but the check in __pm_runtime_set_status() doesn't really cover that situation. For this reason, drop the children check from __pm_runtime_set_status() and add a check against child_count reference counters of "suspended" devices to pm_runtime_enable(). Fixes: a8636c89648a (PM / Runtime: Don't allow to suspend a device with an active child) Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org> Reviewed-by: Johan Hovold <johan@kernel.org>
-rw-r--r--Documentation/power/runtime_pm.txt3
-rw-r--r--drivers/base/power/runtime.c31
2 files changed, 12 insertions, 22 deletions
diff --git a/Documentation/power/runtime_pm.txt b/Documentation/power/runtime_pm.txt
index 57af2f7963ee..937e33c46211 100644
--- a/Documentation/power/runtime_pm.txt
+++ b/Documentation/power/runtime_pm.txt
@@ -435,8 +435,7 @@ drivers/base/power/runtime.c and include/linux/pm_runtime.h:
PM status to 'suspended' and update its parent's counter of 'active'
children as appropriate (it is only valid to use this function if
'power.runtime_error' is set or 'power.disable_depth' is greater than
- zero); it will fail and return an error code if the device has a child
- which is active and the 'power.ignore_children' flag is unset
+ zero)
bool pm_runtime_active(struct device *dev);
- return true if the device's runtime PM status is 'active' or its
diff --git a/drivers/base/power/runtime.c b/drivers/base/power/runtime.c
index 2362b9e9701e..027d159ac381 100644
--- a/drivers/base/power/runtime.c
+++ b/drivers/base/power/runtime.c
@@ -1101,29 +1101,13 @@ int __pm_runtime_set_status(struct device *dev, unsigned int status)
goto out;
}
- if (dev->power.runtime_status == status)
+ if (dev->power.runtime_status == status || !parent)
goto out_set;
if (status == RPM_SUSPENDED) {
- /*
- * It is invalid to suspend a device with an active child,
- * unless it has been set to ignore its children.
- */
- if (!dev->power.ignore_children &&
- atomic_read(&dev->power.child_count)) {
- dev_err(dev, "runtime PM trying to suspend device but active child\n");
- error = -EBUSY;
- goto out;
- }
-
- if (parent) {
- atomic_add_unless(&parent->power.child_count, -1, 0);
- notify_parent = !parent->power.ignore_children;
- }
- goto out_set;
- }
-
- if (parent) {
+ atomic_add_unless(&parent->power.child_count, -1, 0);
+ notify_parent = !parent->power.ignore_children;
+ } else {
spin_lock_nested(&parent->power.lock, SINGLE_DEPTH_NESTING);
/*
@@ -1307,6 +1291,13 @@ void pm_runtime_enable(struct device *dev)
else
dev_warn(dev, "Unbalanced %s!\n", __func__);
+ WARN(!dev->power.disable_depth &&
+ dev->power.runtime_status == RPM_SUSPENDED &&
+ !dev->power.ignore_children &&
+ atomic_read(&dev->power.child_count) > 0,
+ "Enabling runtime PM for inactive device (%s) with active children\n",
+ dev_name(dev));
+
spin_unlock_irqrestore(&dev->power.lock, flags);
}
EXPORT_SYMBOL_GPL(pm_runtime_enable);