cpuidle: governor: Add new governors to cpuidle_governors again

mainline inclusion
from mainline-5.1
commit 22782b3f
category: feature
bugzilla: https://bugzilla.openeuler.org/show_bug.cgi?id=34


CVE: NA

After commit ("cpuidle: Add cpuidle.governor= command
line parameter") new cpuidle governors are not added to the list
of available governors, so governor selection via sysfs doesn't
work as expected (even though it is rarely used anyway).

Fix that by making cpuidle_register_governor() add new governors to
cpuidle_governors again.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Yubo Miao <miaoyubo@huawei.com>
Signed-off-by: Xiangyou Xie <xiexiangyou@huawei.com>
Reviewed-by: Hailiang Zhang <zhang.zhanghailiang@huawei.com>
Reviewed-by: Hanjun Guo <guohanjun@huawei.com>
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
Signed-off-by: Jiajun Chen <chenjiajun8@huawei.com>
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>

drivers/cpuidle/governor.c

@@ -89,6 +89,7 @@ int cpuidle_register_governor(struct cpuidle_governor *gov)
 	mutex_lock(&cpuidle_lock);
 	if (__cpuidle_find_governor(gov->name) == NULL) {
 		ret = 0;
+		list_add_tail(&gov->governor_list, &cpuidle_governors);
 		if (!cpuidle_curr_governor ||
 		    !strncasecmp(param_governor, gov->name, CPUIDLE_NAME_LEN) ||
 		    (cpuidle_curr_governor->rating < gov->rating &&