When using interrupt pin (INT A) as watchdog output all other
interrupt sources need to be disabled to avoid additional
resets. Resulting INT_A_MASK1 value is 55 (0x37).

Signed-off-by: Bruno Thomsen <bruno.thomsen@gmail.com>
---
 drivers/rtc/rtc-pcf2127.c | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/drivers/rtc/rtc-pcf2127.c b/drivers/rtc/rtc-pcf2127.c
index 2e1ac0c42e93..5a39c227203a 100644
--- a/drivers/rtc/rtc-pcf2127.c
+++ b/drivers/rtc/rtc-pcf2127.c
@@ -606,6 +606,21 @@ static int pcf2127_watchdog_init(struct device *dev, struct pcf2127 *pcf2127)
 			set_bit(WDOG_HW_RUNNING, &pcf2127->wdd.status);
 	}
 
+	/*
+	 * When using interrupt pin (INT A) as watchdog output, only allow
+	 * watchdog interrupt (PCF2131_BIT_INT_WD_CD) and disable (mask) all
+	 * other interrupts.
+	 */
+	if (pcf2127->cfg->type == PCF2131) {
+		ret = regmap_write(pcf2127->regmap,
+				   PCF2131_REG_INT_A_MASK1,
+				   PCF2131_BIT_INT_BLIE |
+				   PCF2131_BIT_INT_BIE |
+				   PCF2131_BIT_INT_AIE |
+				   PCF2131_BIT_INT_SI |
+				   PCF2131_BIT_INT_MI);
+	}
+
 	return devm_watchdog_register_device(dev, &pcf2127->wdd);
 }
 

base-commit: b320789d6883cc00ac78ce83bccbfe7ed58afcf0
-- 
2.51.0

On Tue, 02 Sep 2025 20:22:35 +0200, Bruno Thomsen wrote:
> When using interrupt pin (INT A) as watchdog output all other
> interrupt sources need to be disabled to avoid additional
> resets. Resulting INT_A_MASK1 value is 55 (0x37).
> 
> 

Applied, thanks!

[1/1] rtc: pcf2127: fix watchdog interrupt mask on pcf2131
      https://git.kernel.org/abelloni/c/87064da2db7b

Best regards,

-- 
Alexandre Belloni, co-owner and COO, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com