linux-kernel - [PATCH v2] rtc: amlogic-a4: fix double free caused by devm

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Message-ID: <20251021103559.1903-1-vulab@iscas.ac.cn>
Date: Tue, 21 Oct 2025 18:35:59 +0800
From: Haotian Zhang <vulab@...as.ac.cn>
To: alexandre.belloni@...tlin.com,
	yiting.deng@...ogic.com,
	xianwei.zhao@...ogic.com
Cc: linux-amlogic@...ts.infradead.org,
	linux-rtc@...r.kernel.org,
	linux-kernel@...r.kernel.org,
	Haotian Zhang <vulab@...as.ac.cn>
Subject: [PATCH v2] rtc: amlogic-a4: fix double free caused by devm

The clock obtained via devm_clk_get_enabled() is automatically managed
by devres and will be disabled and freed on driver detach. Manually
calling clk_disable_unprepare() in error path and remove function
causes double free.

Remove the redundant clk_disable_unprepare() calls from the probe
error path and aml_rtc_remove(), allowing the devm framework to
automatically manage the clock lifecycle.

Fixes: c89ac9182ee2 ("rtc: support for the Amlogic on-chip RTC")
Signed-off-by: Haotian Zhang <vulab@...as.ac.cn>
---
v2: Also remove the now-unused local variable 'rtc' in aml_rtc_remove()
---
 drivers/rtc/rtc-amlogic-a4.c | 4 ----
 1 file changed, 4 deletions(-)

diff --git a/drivers/rtc/rtc-amlogic-a4.c b/drivers/rtc/rtc-amlogic-a4.c
index 1928b29c1045..a993d35e1d6b 100644
--- a/drivers/rtc/rtc-amlogic-a4.c
+++ b/drivers/rtc/rtc-amlogic-a4.c
@@ -390,7 +390,6 @@ static int aml_rtc_probe(struct platform_device *pdev)
 
 	return 0;
 err_clk:
-	clk_disable_unprepare(rtc->sys_clk);
 	device_init_wakeup(dev, false);
 
 	return ret;
@@ -423,9 +422,6 @@ static SIMPLE_DEV_PM_OPS(aml_rtc_pm_ops,
 
 static void aml_rtc_remove(struct platform_device *pdev)
 {
-	struct aml_rtc_data *rtc = dev_get_drvdata(&pdev->dev);
-
-	clk_disable_unprepare(rtc->sys_clk);
 	device_init_wakeup(&pdev->dev, false);
 }
 
-- 
2.25.1