From a8636c89648ab12e59d8f3aa667ec76fc96fd643 Mon Sep 17 00:00:00 2001 From: Ulf Hansson Date: Mon, 17 Oct 2016 20:17:01 +0200 Subject: [PATCH] PM / Runtime: Don't allow to suspend a device with an active child When resuming a device in __pm_runtime_set_status(), the prerequisite is that its parent must already be active, else an error code is returned and the device's status remains suspended. When suspending a device there is no similar constraints being validated. Let's change this to make the behaviour consistent, by not allowing to suspend a device with an active child, unless it has been explicitly set to ignore its children. Signed-off-by: Ulf Hansson Reviewed-by: Linus Walleij Signed-off-by: Rafael J. Wysocki --- drivers/base/power/runtime.c | 12 +++++++++++- 1 file changed, 11 insertions(+), 1 deletion(-) diff --git a/drivers/base/power/runtime.c b/drivers/base/power/runtime.c index 117db71e84cb..60ebb04d8140 100644 --- a/drivers/base/power/runtime.c +++ b/drivers/base/power/runtime.c @@ -1028,7 +1028,17 @@ int __pm_runtime_set_status(struct device *dev, unsigned int status) goto out_set; if (status == RPM_SUSPENDED) { - /* It always is possible to set the status to '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; -- 2.20.1