From b48ee1f7404a17138785cb3ceb6a95e96b489c0d Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Sat, 14 Mar 2026 13:12:44 +0100 Subject: [PATCH] rtc: cmos: Do not require IRQ if ACPI alarm is used If the ACPI RTC fixed event is used, a dedicated IRQ is not required for the CMOS RTC alarm to work, so allow the driver to use the alarm without a valid IRQ in that case. Signed-off-by: Rafael J. Wysocki Acked-by: Alexandre Belloni Reviewed-by: Mario Limonciello (AMD) Link: https://patch.msgid.link/6168746.MhkbZ0Pkbq@rafael.j.wysocki --- drivers/rtc/rtc-cmos.c | 15 ++++++++++----- 1 file changed, 10 insertions(+), 5 deletions(-) diff --git a/drivers/rtc/rtc-cmos.c b/drivers/rtc/rtc-cmos.c index 221e7525cd3f..acc064baefcd 100644 --- a/drivers/rtc/rtc-cmos.c +++ b/drivers/rtc/rtc-cmos.c @@ -216,6 +216,11 @@ static inline void cmos_write_bank2(unsigned char val, unsigned char addr) /*----------------------------------------------------------------*/ +static bool cmos_no_alarm(struct cmos_rtc *cmos) +{ + return !is_valid_irq(cmos->irq) && !cmos_use_acpi_alarm(); +} + static int cmos_read_time(struct device *dev, struct rtc_time *t) { int ret; @@ -287,7 +292,7 @@ static int cmos_read_alarm(struct device *dev, struct rtc_wkalrm *t) }; /* This not only a rtc_op, but also called directly */ - if (!is_valid_irq(cmos->irq)) + if (cmos_no_alarm(cmos)) return -ETIMEDOUT; /* Basic alarms only support hour, minute, and seconds fields. @@ -520,7 +525,7 @@ static int cmos_set_alarm(struct device *dev, struct rtc_wkalrm *t) int ret; /* This not only a rtc_op, but also called directly */ - if (!is_valid_irq(cmos->irq)) + if (cmos_no_alarm(cmos)) return -EIO; ret = cmos_validate_alarm(dev, t); @@ -1096,7 +1101,7 @@ cmos_do_probe(struct device *dev, struct resource *ports, int rtc_irq) dev_dbg(dev, "IRQ %d is already in use\n", rtc_irq); goto cleanup1; } - } else { + } else if (!cmos_use_acpi_alarm()) { clear_bit(RTC_FEATURE_ALARM, cmos_rtc.rtc->features); } @@ -1121,7 +1126,7 @@ cmos_do_probe(struct device *dev, struct resource *ports, int rtc_irq) acpi_rtc_event_setup(dev); dev_info(dev, "%s%s, %d bytes nvram%s\n", - !is_valid_irq(rtc_irq) ? "no alarms" : + cmos_no_alarm(&cmos_rtc) ? "no alarms" : cmos_rtc.mon_alrm ? "alarms up to one year" : cmos_rtc.day_alrm ? "alarms up to one month" : "alarms up to one day", @@ -1147,7 +1152,7 @@ cleanup0: static void cmos_do_shutdown(int rtc_irq) { spin_lock_irq(&rtc_lock); - if (is_valid_irq(rtc_irq)) + if (!cmos_no_alarm(&cmos_rtc)) cmos_irq_disable(&cmos_rtc, RTC_IRQMASK); spin_unlock_irq(&rtc_lock); }