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

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Message-ID: <20250702073224.2684097-1-andriy.shevchenko@linux.intel.com>
Date: Wed,  2 Jul 2025 10:32:24 +0300
From: Andy Shevchenko <andriy.shevchenko@...ux.intel.com>
To: Andy Shevchenko <andriy.shevchenko@...ux.intel.com>,
	linux-rtc@...r.kernel.org,
	linux-kernel@...r.kernel.org
Cc: Alexandre Belloni <alexandre.belloni@...tlin.com>
Subject: [PATCH v1 1/1] rtc: sysfs: Bail out earlier if no new groups provided

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@...ux.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