Revert "[CPUFREQ] Disable sysfs ui for p4-clockmod."

This reverts commit e088e4c9.

Removing the sysfs interface for p4-clockmod was flagged as a
regression in bug 12826.

Course of action:
 - Find out the remaining causes of overheating, and fix them
   if possible. ACPI should be doing the right thing automatically.
   If it isn't, we need to fix that.
 - mark p4-clockmod ui as deprecated
 - try again with the removal in six months.

It's not really feasible to printk about the deprecation, because
it needs to happen at all the sysfs entry points, which means adding
a lot of strcmp("p4-clockmod".. calls to the core, which.. bleuch.
Signed-off-by: Dave Jones <davej@redhat.com>

arch/x86/kernel/cpu/cpufreq/p4-clockmod.c

@@ -277,7 +277,6 @@ static struct cpufreq_driver p4clockmod_driver = {
 	.name		= "p4-clockmod",
 	.owner		= THIS_MODULE,
 	.attr		= p4clockmod_attr,
-	.hide_interface	= 1,
 };
 
 

drivers/cpufreq/cpufreq.c

@@ -754,11 +754,6 @@ static struct kobj_type ktype_cpufreq = {
 	.release	= cpufreq_sysfs_release,
 };
 
-static struct kobj_type ktype_empty_cpufreq = {
-	.sysfs_ops	= &sysfs_ops,
-	.release	= cpufreq_sysfs_release,
-};
-
 
 /**
  * cpufreq_add_dev - add a CPU device
@@ -892,36 +887,26 @@ static int cpufreq_add_dev(struct sys_device *sys_dev)
 	memcpy(&new_policy, policy, sizeof(struct cpufreq_policy));
 
 	/* prepare interface data */
-	if (!cpufreq_driver->hide_interface) {
-		ret = kobject_init_and_add(&policy->kobj, &ktype_cpufreq,
-					   &sys_dev->kobj, "cpufreq");
+	ret = kobject_init_and_add(&policy->kobj, &ktype_cpufreq, &sys_dev->kobj,
+				   "cpufreq");
+	if (ret)
+		goto err_out_driver_exit;
+
+	/* set up files for this cpu device */
+	drv_attr = cpufreq_driver->attr;
+	while ((drv_attr) && (*drv_attr)) {
+		ret = sysfs_create_file(&policy->kobj, &((*drv_attr)->attr));
 		if (ret)
 			goto err_out_driver_exit;
-
-		/* set up files for this cpu device */
-		drv_attr = cpufreq_driver->attr;
-		while ((drv_attr) && (*drv_attr)) {
-			ret = sysfs_create_file(&policy->kobj,
-						&((*drv_attr)->attr));
-			if (ret)
-				goto err_out_driver_exit;
-			drv_attr++;
-		}
-		if (cpufreq_driver->get) {
-			ret = sysfs_create_file(&policy->kobj,
-						&cpuinfo_cur_freq.attr);
-			if (ret)
-				goto err_out_driver_exit;
-		}
-		if (cpufreq_driver->target) {
-			ret = sysfs_create_file(&policy->kobj,
-						&scaling_cur_freq.attr);
-			if (ret)
-				goto err_out_driver_exit;
-		}
-	} else {
-		ret = kobject_init_and_add(&policy->kobj, &ktype_empty_cpufreq,
-					   &sys_dev->kobj, "cpufreq");
+		drv_attr++;
+	}
+	if (cpufreq_driver->get) {
+		ret = sysfs_create_file(&policy->kobj, &cpuinfo_cur_freq.attr);
+		if (ret)
+			goto err_out_driver_exit;
+	}
+	if (cpufreq_driver->target) {
+		ret = sysfs_create_file(&policy->kobj, &scaling_cur_freq.attr);
 		if (ret)
 			goto err_out_driver_exit;
 	}

include/linux/cpufreq.h

@@ -234,7 +234,6 @@ struct cpufreq_driver {
 	int	(*suspend)	(struct cpufreq_policy *policy, pm_message_t pmsg);
 	int	(*resume)	(struct cpufreq_policy *policy);
 	struct freq_attr	**attr;
-	bool			hide_interface;
 };
 
 /* flags */