Commit 74d612a3 authored Mar 03, 2025 by Ming Wang Committed by Hongchen Zhang Mar 03, 2025

rtc: loongson: clear TOY_MATCH0_REG in loongson_rtc_isr()

stable inclusion
from stable-v6.6.76
commit 20f0f55e6d686eae7934e28358ea446e36cff77f
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/IBQ4JL
CVE: NA
Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=20f0f55e6d686eae7934e28358ea446e36cff77f



--------------------------------

The TOY_MATCH0_REG should be cleared to 0 in the RTC interrupt handler,
otherwise the interrupt cannot be cleared, which will cause the
loongson_rtc_isr() to be triggered multiple times.

The previous code cleared TOY_MATCH0_REG in the loongson_rtc_handler(),
which is an ACPI interrupt. This did not prevent loongson_rtc_isr()
from being triggered multiple times.

This commit moves the clearing of TOY_MATCH0_REG to the
loongson_rtc_isr() to ensure that the interrupt is properly cleared.

Fixes: 1b733a9e ("rtc: Add rtc driver for the Loongson family chips")
Signed-off-by: Ming Wang <wangming01@loongson.cn>
Reviewed-by: Huacai Chen <chenhuacai@loongson.cn>
Reviewed-by: Keguang Zhang <keguang.zhang@gmail.com> # on LS1B
Tested-by: Keguang Zhang <keguang.zhang@gmail.com>

parent 508590df

drivers/rtc/rtc-loongson.c

+8 −5

Original line number	Diff line number	Diff line
		@@ -114,6 +114,13 @@ static irqreturn_t loongson_rtc_isr(int irq, void *id)
		struct loongson_rtc_priv priv = (struct loongson_rtc_priv )id;

		rtc_update_irq(priv->rtcdev, 1, RTC_AF \| RTC_IRQF);

		/*
		* The TOY_MATCH0_REG should be cleared 0 here,
		* otherwise the interrupt cannot be cleared.
		*/
		regmap_write(priv->regmap, TOY_MATCH0_REG, 0);

		return IRQ_HANDLED;
		}

		@@ -131,11 +138,7 @@ static u32 loongson_rtc_handler(void *id)
		writel(RTC_STS, priv->pm_base + PM1_STS_REG);
		spin_unlock(&priv->lock);

		/*
		* The TOY_MATCH0_REG should be cleared 0 here,
		* otherwise the interrupt cannot be cleared.
		*/
		return regmap_write(priv->regmap, TOY_MATCH0_REG, 0);
		return ACPI_INTERRUPT_HANDLED;
		}

		static int loongson_rtc_set_enabled(struct device *dev)