[CPUFREQ] new cpufreq_driver->resume callback, needed (at least) for speedstep-smi.

Documentation/cpu-freq/cpu-drivers.txt

@@ -64,6 +64,12 @@ And optionally
 
 cpufreq_driver.exit -		A pointer to a per-CPU cleanup function.
 
+cpufreq_driver.resume -		A pointer to a per-CPU resume function
+				which is called with interrupts disabled
+				and _before_ the pre-suspend frequency
+				and/or policy is restored by a call to
+				->target or ->setpolicy.
+
 cpufreq_driver.attr -		A pointer to a NULL-terminated list of
 				"struct freq_attr" which allow to
 				export values to sysfs.

drivers/cpufreq/cpufreq.c

@@ -495,6 +495,13 @@ static int cpufreq_resume(struct sys_device * sysdev)
 	if (!cpu_policy)
 		return -EINVAL;
 
+	if (cpufreq_driver->resume)
+		ret = cpufreq_driver->resume(cpu_policy);
+	if (ret) {
+		printk(KERN_ERR "cpufreq: resume failed in ->resume step on CPU %u\n", cpu_policy->cpu);
+		goto out;
+	}
+
 	if (cpufreq_driver->setpolicy)
 		ret = cpufreq_driver->setpolicy(cpu_policy);
 	else
@@ -503,6 +510,12 @@ static int cpufreq_resume(struct sys_device * sysdev)
 	 */
 		ret = cpufreq_driver->target(cpu_policy, cpu_policy->cur, CPUFREQ_RELATION_H);
 
+	if (ret) {
+		printk(KERN_ERR "cpufreq: resume failed in ->setpolicy/target step on CPU %u\n", cpu_policy->cpu);
+		goto out;
+	}
+
+ out:
 	cpufreq_cpu_put(cpu_policy);
 
 	return ret;

include/linux/cpufreq.h

@@ -179,6 +179,7 @@ struct cpufreq_driver {
 
 	/* optional */
 	int	(*exit)		(struct cpufreq_policy *policy);
+	int	(*resume)	(struct cpufreq_policy *policy);
 	struct freq_attr	**attr;
 };