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PM-runtime: Take suppliers into account in __pm_runtime_set_status()

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If the target device has any suppliers, as reflected by device links
to them, __pm_runtime_set_status() does not take them into account,
which is not consistent with the other parts of the PM-runtime
framework and may lead to programming mistakes.

Modify __pm_runtime_set_status() to take suppliers into account by
activating them upfront if the new status is RPM_ACTIVE and
deactivating them on exit if the new status is RPM_SUSPENDED.

If the activation of one of the suppliers fails, the new status
will be RPM_SUSPENDED and the (remaining) suppliers will be
deactivated on exit (the child count of the device's parent
will be dropped too then).

Of course, adding device links locking to __pm_runtime_set_status()
means that it cannot be run fron interrupt context, so make it use
spin_lock_irq() and spin_unlock_irq() instead of spin_lock_irqsave()
and spin_unlock_irqrestore(), respectively.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Rafael J. Wysocki 2019-02-07 19:38:56 +01:00 committed by Greg Kroah-Hartman
parent 79a4e91d1b
commit 4080ab0830
1 changed files with 40 additions and 5 deletions
repo.diff.show_diff_stats Download patch file Download diff file Expand all files Collapse all files

45
drivers/base/power/runtime.c
View file

@ -1089,20 +1089,43 @@ EXPORT_SYMBOL_GPL(pm_runtime_get_if_in_use);
* and the device parent's counter of unsuspended children is modified to * and the device parent's counter of unsuspended children is modified to
* reflect the new status. If the new status is RPM_SUSPENDED, an idle * reflect the new status. If the new status is RPM_SUSPENDED, an idle
* notification request for the parent is submitted. * notification request for the parent is submitted.
*
* If @dev has any suppliers (as reflected by device links to them), and @status
* is RPM_ACTIVE, they will be activated upfront and if the activation of one
* of them fails, the status of @dev will be changed to RPM_SUSPENDED (instead
* of the @status value) and the suppliers will be deacticated on exit. The
* error returned by the failing supplier activation will be returned in that
* case.
*/ */
int __pm_runtime_set_status(struct device *dev, unsigned int status) int __pm_runtime_set_status(struct device *dev, unsigned int status)
{ {
struct device *parent = dev->parent; struct device *parent = dev->parent;
unsigned long flags;
bool notify_parent = false; bool notify_parent = false;
int error = 0; int error = 0;
if (status != RPM_ACTIVE && status != RPM_SUSPENDED) if (status != RPM_ACTIVE && status != RPM_SUSPENDED)
return -EINVAL; return -EINVAL;
spin_lock_irqsave(&dev->power.lock, flags); /*
* If the new status is RPM_ACTIVE, the suppliers can be activated
* upfront regardless of the current status, because next time
* rpm_put_suppliers() runs, the rpm_active refcounts of the links
* involved will be dropped down to one anyway.
*/
if (status == RPM_ACTIVE) {
int idx = device_links_read_lock();
error = rpm_get_suppliers(dev);
if (error)
status = RPM_SUSPENDED;
device_links_read_unlock(idx);
}
spin_lock_irq(&dev->power.lock);
if (!dev->power.runtime_error && !dev->power.disable_depth) { if (!dev->power.runtime_error && !dev->power.disable_depth) {
status = dev->power.runtime_status;
error = -EAGAIN; error = -EAGAIN;
goto out; goto out;
} }
@ -1134,19 +1157,31 @@ int __pm_runtime_set_status(struct device *dev, unsigned int status)
spin_unlock(&parent->power.lock); spin_unlock(&parent->power.lock);
if (error) if (error) {
status = RPM_SUSPENDED;
goto out; goto out;
}
} }
out_set: out_set:
__update_runtime_status(dev, status); __update_runtime_status(dev, status);
dev->power.runtime_error = 0; if (!error)
dev->power.runtime_error = 0;
out: out:
spin_unlock_irqrestore(&dev->power.lock, flags); spin_unlock_irq(&dev->power.lock);
if (notify_parent) if (notify_parent)
pm_request_idle(parent); pm_request_idle(parent);
if (status == RPM_SUSPENDED) {
int idx = device_links_read_lock();
rpm_put_suppliers(dev);
device_links_read_unlock(idx);
}
return error; return error;
} }
EXPORT_SYMBOL_GPL(__pm_runtime_set_status); EXPORT_SYMBOL_GPL(__pm_runtime_set_status);