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

[ Upstream commit 32b1133a4bde4a73f6af41841a28ddaa914d6875 ]

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>

diff --git a/drivers/base/power/runtime.c b/drivers/base/power/runtime.c
index 8fbd376471de05a42a8723f837e65c5a8068042c..24a3013728c3dfb677ccc1d88089d9749bfcd2bd 100644 (file)
--- a/drivers/base/power/runtime.c
+++ b/drivers/base/power/runtime.c
@@ -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. */
@@ -462,10 +465,7 @@ 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);
+       retval = __rpm_callback(callback, dev);
 
        dev->power.idle_notification = false;
        wake_up_all(&dev->power.wait_queue);