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From: Cong Nguyen <congnt264@gmail.com>
To: Jacky Huang <ychuang3@nuvoton.com>
Cc: Shan-Chun Hung <schung@nuvoton.com>,
	Alexandre Belloni <alexandre.belloni@bootlin.com>,
	linux-arm-kernel@lists.infradead.org, linux-rtc@vger.kernel.org,
	linux-kernel@vger.kernel.org
Subject: [PATCH] rtc: ma35d1: fix permanent clock reference/enable-count leak in probe
Date: Mon, 14 Sep 2026 20:18:50 +0700	[thread overview]
Message-ID: <20260914131850.2331670-1-congnt264@gmail.com> (raw)

ma35d1_rtc_probe() gets the RTC clock via of_clk_get() and enables it
via clk_prepare_enable(), but the struct clk * is a local variable --
never stored anywhere, and the driver has no .remove. So on every
probe, success or failure, there's no way to ever call
clk_disable_unprepare()/clk_put() on it -- a permanent leak, and since
CONFIG_RTC_DRV_MA35D1 is tristate, each module load/unload leaks
another one.

Replace of_clk_get() + clk_prepare_enable() with
devm_clk_get_enabled() -- same clock (both route through
__of_clk_get(np, 0, ...)) but devm-managed, so it's released
automatically on unbind or any probe-failure return.

Fixes: dc0684adf3b6 ("rtc: Add driver for Nuvoton ma35d1 rtc controller")
Assisted-by: Claude:claude-opus-4
Signed-off-by: Cong Nguyen <congnt264@gmail.com>
---
 drivers/rtc/rtc-ma35d1.c | 6 +-----
 1 file changed, 1 insertion(+), 5 deletions(-)

diff --git a/drivers/rtc/rtc-ma35d1.c b/drivers/rtc/rtc-ma35d1.c
index cfcfc28060f6..43358d68565a 100644
--- a/drivers/rtc/rtc-ma35d1.c
+++ b/drivers/rtc/rtc-ma35d1.c
@@ -221,14 +221,10 @@ static int ma35d1_rtc_probe(struct platform_device *pdev)
 	if (IS_ERR(rtc->rtc_reg))
 		return PTR_ERR(rtc->rtc_reg);
 
-	clk = of_clk_get(pdev->dev.of_node, 0);
+	clk = devm_clk_get_enabled(&pdev->dev, NULL);
 	if (IS_ERR(clk))
 		return dev_err_probe(&pdev->dev, PTR_ERR(clk), "failed to find rtc clock\n");
 
-	ret = clk_prepare_enable(clk);
-	if (ret)
-		return ret;
-
 	if (!(rtc_reg_read(rtc, MA35_REG_RTC_INIT) & RTC_INIT_ACTIVE)) {
 		ret = ma35d1_rtc_init(rtc, RTC_INIT_TIMEOUT);
 		if (ret)
-- 
2.25.1



             reply	other threads:[~2026-09-14 13:19 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-09-14 13:18 Cong Nguyen [this message]
2026-09-14 13:35 ` [PATCH] rtc: ma35d1: fix permanent clock reference/enable-count leak in probe sashiko-bot
2026-09-15  6:08 ` Jacky Huang

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