[PATCH v1 1/1] rtc: sysfs: Bail out earlier if no new groups provided

[Andy Shevchenko <andriy.shevchenko@linux.intel.com>]

When there is no new groups provided, no need to reallocate memory,
copy the old ones and free them in order to do nothing. Do nothing
instead.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
---
 drivers/rtc/sysfs.c | 12 ++++++++----
 1 file changed, 8 insertions(+), 4 deletions(-)

diff --git a/drivers/rtc/sysfs.c b/drivers/rtc/sysfs.c
index 2230241285d0..4ab05e105a76 100644
--- a/drivers/rtc/sysfs.c
+++ b/drivers/rtc/sysfs.c
@@ -310,17 +310,21 @@ int rtc_add_groups(struct rtc_device *rtc, const struct attribute_group **grps)
 	size_t old_cnt = 0, add_cnt = 0, new_cnt;
 	const struct attribute_group **groups, **old;
 
-	if (!grps)
+	if (grps) {
+		for (groups = grps; *groups; groups++)
+			add_cnt++;
+		/* No need to modify current groups if nothing new is provided */
+		if (add_cnt == 0)
+			return 0;
+	} else {
 		return -EINVAL;
+	}
 
 	groups = rtc->dev.groups;
 	if (groups)
 		for (; *groups; groups++)
 			old_cnt++;
 
-	for (groups = grps; *groups; groups++)
-		add_cnt++;
-
 	new_cnt = old_cnt + add_cnt + 1;
 	groups = devm_kcalloc(&rtc->dev, new_cnt, sizeof(*groups), GFP_KERNEL);
 	if (!groups)
-- 
2.47.2