From 51458d5b0a1cfb1b6013400abc95aadf16ed2a57 Mon Sep 17 00:00:00 2001 From: Lad Prabhakar Date: Fri, 21 Aug 2026 22:10:21 +0100 Subject: [PATCH] rtc: rzn1: Disable alarm interrupt before reprogramming alarm registers rzn1_rtc_set_alarm() updates RZN1_RTC_ALM, RZN1_RTC_ALH and RZN1_RTC_ALW using separate MMIO writes without first disabling the alarm interrupt. If a previous alarm is still enabled, the interrupt can fire while the alarm registers contain a mixture of old and newly written values. Fix this by disabling the alarm interrupt before reprogramming ALM, ALH and ALW with a call to rzn1_rtc_alarm_irq_enable(). Fixes: b5ad1bf00d2c4 ("rtc: rzn1: Add alarm support") Cc: stable@vger.kernel.org Signed-off-by: Lad Prabhakar Reviewed-by: Wolfram Sang Tested-by: Wolfram Sang Link: https://patch.msgid.link/20260821211032.13554-7-prabhakar.mahadev-lad.rj@bp.renesas.com Signed-off-by: Alexandre Belloni --- drivers/rtc/rtc-rzn1.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/drivers/rtc/rtc-rzn1.c b/drivers/rtc/rtc-rzn1.c index f3268655fd37..42e57bf0b4aa 100644 --- a/drivers/rtc/rtc-rzn1.c +++ b/drivers/rtc/rtc-rzn1.c @@ -281,6 +281,11 @@ static int rzn1_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm) if (alarm > farest) return -ERANGE; + /* Disable alarm interrupts before reprogramming the alarm. */ + ret = rzn1_rtc_alarm_irq_enable(dev, 0); + if (ret) + return ret; + writel(bin2bcd(tm->tm_min), rtc->base + RZN1_RTC_ALM); writel(bin2bcd(tm->tm_hour), rtc->base + RZN1_RTC_ALH); writel(BIT(tm->tm_wday), rtc->base + RZN1_RTC_ALW);