X-Git-Url: http://git.samba.org/samba.git/?p=sfrench%2Fcifs-2.6.git;a=blobdiff_plain;f=drivers%2Fcpuidle%2Fcpuidle.c;h=a507108433785f8432b3d15504c3a036b461c1a0;hp=dbefe15bd582804497cbca76b6f3ce4fae6e28da;hb=71abbbf856a0e70ca478782505c800891260ba84;hpb=90c8327cad5d7c2d5d7d3e761d17af1925474107

diff --git a/drivers/cpuidle/cpuidle.c b/drivers/cpuidle/cpuidle.c
index dbefe15bd582..a50710843378 100644
--- a/drivers/cpuidle/cpuidle.c
+++ b/drivers/cpuidle/cpuidle.c
@@ -74,6 +74,17 @@ static void cpuidle_idle_call(void)
 	 */
 	hrtimer_peek_ahead_timers();
 #endif
+
+	/*
+	 * Call the device's prepare function before calling the
+	 * governor's select function.  ->prepare gives the device's
+	 * cpuidle driver a chance to update any dynamic information
+	 * of its cpuidle states for the current idle period, e.g.
+	 * state availability, latencies, residencies, etc.
+	 */
+	if (dev->prepare)
+		dev->prepare(dev);
+
 	/* ask the governor for the next state */
 	next_state = cpuidle_curr_governor->select(dev);
 	if (need_resched()) {
@@ -282,6 +293,26 @@ static int __cpuidle_register_device(struct cpuidle_device *dev)
 
 	poll_idle_init(dev);
 
+	/*
+	 * cpuidle driver should set the dev->power_specified bit
+	 * before registering the device if the driver provides
+	 * power_usage numbers.
+	 *
+	 * For those devices whose ->power_specified is not set,
+	 * we fill in power_usage with decreasing values as the
+	 * cpuidle code has an implicit assumption that state Cn
+	 * uses less power than C(n-1).
+	 *
+	 * With CONFIG_ARCH_HAS_CPU_RELAX, C0 is already assigned
+	 * an power value of -1.  So we use -2, -3, etc, for other
+	 * c-states.
+	 */
+	if (!dev->power_specified) {
+		int i;
+		for (i = CPUIDLE_DRIVER_STATE_START; i < dev->state_count; i++)
+			dev->states[i].power_usage = -1 - i;
+	}
+
 	per_cpu(cpuidle_devices, dev->cpu) = dev;
 	list_add(&dev->device_list, &cpuidle_detected_devices);
 	if ((ret = cpuidle_add_sysfs(sys_dev))) {