PM-runtime: Optimize pm_runtime_autosuspend_expiration()

pm_runtime_autosuspend_expiration calls ktime_get_mono_fast_ns()
even when its returned value may be unused. Therefore get the
current time later and remove gotos while there.

Signed-off-by: Ladislav Michl <ladis@linux-mips.org>
Acked-by: Tony Lindgren <tony@atomide.com>
Acked-by: Vincent Guittot <vincent.guittot@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

diff --git a/drivers/base/power/runtime.c b/drivers/base/power/runtime.c
index 4eaf166..1caa394 100644 (file)
--- a/drivers/base/power/runtime.c
+++ b/drivers/base/power/runtime.c
@@ -145,24 +145,21 @@ static void pm_runtime_cancel_pending(struct device *dev)
 u64 pm_runtime_autosuspend_expiration(struct device *dev)
 {
        int autosuspend_delay;
-       u64 last_busy, expires = 0;
-       u64 now = ktime_get_mono_fast_ns();
+       u64 expires;
 
        if (!dev->power.use_autosuspend)
-               goto out;
+               return 0;
 
        autosuspend_delay = READ_ONCE(dev->power.autosuspend_delay);
        if (autosuspend_delay < 0)
-               goto out;
-
-       last_busy = READ_ONCE(dev->power.last_busy);
+               return 0;
 
-       expires = last_busy + (u64)autosuspend_delay * NSEC_PER_MSEC;
-       if (expires <= now)
-               expires = 0;    /* Already expired. */
+       expires  = READ_ONCE(dev->power.last_busy);
+       expires += (u64)autosuspend_delay * NSEC_PER_MSEC;
+       if (expires > ktime_get_mono_fast_ns())
+               return expires; /* Expires in the future */
 
- out:
-       return expires;
+       return 0;
 }
 EXPORT_SYMBOL_GPL(pm_runtime_autosuspend_expiration);