6.6-stable review patch. If anyone has any objections, please let me know.
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From: Liu Dalin liudalin@kylinsec.com.cn
[ Upstream commit 5af9f1fa576874b24627d4c05e3a84672204c200 ]
When an application sets and enables an alarm on Loongson RTC devices, the alarm notification fails to propagate to userspace because the ACPI event handler omits calling rtc_update_irq().
As a result, processes waiting via select() or poll() on RTC device files fail to receive alarm notifications.
The ACPI interrupt is also triggered multiple times. In loongson_rtc_handler, we need to clear TOY_MATCH0_REG to resolve this issue.
Fixes: 09471d8f5b39 ("rtc: loongson: clear TOY_MATCH0_REG in loongson_rtc_isr()") Fixes: 1b733a9ebc3d ("rtc: Add rtc driver for the Loongson family chips") Signed-off-by: Liu Dalin liudalin@kylinsec.com.cn Reviewed-by: Binbin Zhou zhoubinbin@loongson.cn Link: https://lore.kernel.org/r/20250509084416.7979-1-liudalin@kylinsec.com.cn Signed-off-by: Alexandre Belloni alexandre.belloni@bootlin.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/rtc/rtc-loongson.c | 8 ++++++++ 1 file changed, 8 insertions(+)
diff --git a/drivers/rtc/rtc-loongson.c b/drivers/rtc/rtc-loongson.c index 90e9d97a86b48..c9d5b91a6544d 100644 --- a/drivers/rtc/rtc-loongson.c +++ b/drivers/rtc/rtc-loongson.c @@ -129,6 +129,14 @@ static u32 loongson_rtc_handler(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); + spin_lock(&priv->lock); /* Disable RTC alarm wakeup and interrupt */ writel(readl(priv->pm_base + PM1_EN_REG) & ~RTC_EN,