[PATCH v2] rtc: stm32: fix clock leak on pinctrl probe failure

[Cong Nguyen <congnt264@gmail.com>]

A failing devm_pinctrl_register_and_init() or pinctrl_enable() in
stm32_rtc_probe() returns directly instead of going through err:,
leaking rtc_ck/pclk -- and since -EPROBE_DEFER is routine here, each
deferred retry leaks another.

Route both through err:, and move the pinctrl setup earlier (right
after stm32_rtc_init(), before the RTC device/IRQ are registered) so
disabling the clocks there doesn't race a still-live IRQ.

Fixes: 16ad2bc09efb ("rtc: stm32: add pinctrl and pinmux interfaces")
Reported-by: Sashiko AI review <sashiko-bot@kernel.org>
Link: https://lore.kernel.org/r/20260914135401.373D91F000FF@smtp.kernel.org
Assisted-by: LLM
Signed-off-by: Cong Nguyen <congnt264@gmail.com>
---
Changes in v2:
- Sashiko found that routing the pinctrl failures through err: (as v1
  did) disables the clocks while the still-registered RTC device and
  alarm IRQ are live. Moved the pinctrl setup earlier instead of just
  moving where the leak was plugged.

 drivers/rtc/rtc-stm32.c | 24 ++++++++++++++----------
 1 file changed, 14 insertions(+), 10 deletions(-)

diff --git a/drivers/rtc/rtc-stm32.c b/drivers/rtc/rtc-stm32.c
index d4ebf3eb54aa..457f66663ba5 100644
--- a/drivers/rtc/rtc-stm32.c
+++ b/drivers/rtc/rtc-stm32.c
@@ -1137,6 +1137,20 @@ static int stm32_rtc_probe(struct platform_device *pdev)
 	if (ret)
 		goto err;
 
+	stm32_rtc_clean_outs(rtc);
+
+	ret = devm_pinctrl_register_and_init(&pdev->dev, &stm32_rtc_pdesc, rtc, &pctl);
+	if (ret) {
+		dev_err_probe(&pdev->dev, ret, "pinctrl register failed");
+		goto err;
+	}
+
+	ret = pinctrl_enable(pctl);
+	if (ret) {
+		dev_err_probe(&pdev->dev, ret, "pinctrl enable failed");
+		goto err;
+	}
+
 	rtc->irq_alarm = platform_get_irq(pdev, 0);
 	if (rtc->irq_alarm <= 0) {
 		ret = rtc->irq_alarm;
@@ -1172,16 +1186,6 @@ static int stm32_rtc_probe(struct platform_device *pdev)
 		goto err;
 	}
 
-	stm32_rtc_clean_outs(rtc);
-
-	ret = devm_pinctrl_register_and_init(&pdev->dev, &stm32_rtc_pdesc, rtc, &pctl);
-	if (ret)
-		return dev_err_probe(&pdev->dev, ret, "pinctrl register failed");
-
-	ret = pinctrl_enable(pctl);
-	if (ret)
-		return dev_err_probe(&pdev->dev, ret, "pinctrl enable failed");
-
 	/*
 	 * If INITS flag is reset (calendar year field set to 0x00), calendar
 	 * must be initialized
-- 
2.25.1