Commit c40ee4e0 authored Jun 08, 2021 by Ulf Hansson Committed by Greg Kroah-Hartman Jan 18, 2023

PM: runtime: Improve path in rpm_idle() when no callback



[ Upstream commit 5a2bd1b1c64e1ac5627db3767ac465f18606315c ]

When pm_runtime_no_callbacks() has been called for a struct device to set
the dev->power.no_callbacks flag for it, it enables rpm_idle() to take a
slightly quicker path by assuming that a ->runtime_idle() callback would
have returned 0 to indicate success.

A device that does not have the dev->power.no_callbacks flag set for it,
may still be missing a corresponding ->runtime_idle() callback, in which
case the slower path in rpm_idle() is taken. Let's improve the behaviour
for this case, by aligning code to the quicker path.

Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Stable-dep-of: bc80c2e438dc ("PM: runtime: Do not call __rpm_callback() from rpm_idle()")
Signed-off-by: Sasha Levin <sashal@kernel.org>

parent 4f983ee5

drivers/base/power/runtime.c

+5 −5

Original line number	Diff line number	Diff line
		@@ -446,7 +446,10 @@ static int rpm_idle(struct device *dev, int rpmflags)
		/* Pending requests need to be canceled. */
		dev->power.request = RPM_REQ_NONE;

		if (dev->power.no_callbacks)
		callback = RPM_GET_CALLBACK(dev, runtime_idle);

		/* If no callback assume success. */
		if (!callback \|\| dev->power.no_callbacks)
		goto out;

		/* Carry out an asynchronous or a synchronous idle notification. */
		@@ -462,9 +465,6 @@ static int rpm_idle(struct device *dev, int rpmflags)

		dev->power.idle_notification = true;

		callback = RPM_GET_CALLBACK(dev, runtime_idle);

		if (callback)
		retval = __rpm_callback(callback, dev);

		dev->power.idle_notification = false;