Converting from ms to s requires dividing by 1000, not multiplying. So this is currently taking the smaller of new_timeout and 1.28e8, i.e. effectively new_timeout. The driver knows what it set max_hw_heartbeat_ms to, so use that value instead of doing a division at run-time. FWIW, this can easily be tested by booting into a busybox shell and doing "watchdog -t 5 -T 130 /dev/watchdog" - without this patch, the watchdog fires after 130&127 == 2 seconds. Fixes: b07e228eee69 "watchdog: imx2_wdt: Fix set_timeout for big timeout values" Cc: stable@xxxxxxxxxxxxxxx # 5.2 plus anything the above got backported to Signed-off-by: Rasmus Villemoes <linux@xxxxxxxxxxxxxxxxxx> --- This should really be handled in the watchdog core for any driver that reports max_hw_heartbeat_ms. The same pattern appears in aspeed_wdt.c. I don't have the hardware, but s#wdd->max_hw_heartbeat_ms * 1000#WDT_MAX_TIMEOUT_MS/1000U# should fix that one. drivers/watchdog/imx2_wdt.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/watchdog/imx2_wdt.c b/drivers/watchdog/imx2_wdt.c index 32af3974e6bb..8d019a961ccc 100644 --- a/drivers/watchdog/imx2_wdt.c +++ b/drivers/watchdog/imx2_wdt.c @@ -55,7 +55,7 @@ #define IMX2_WDT_WMCR 0x08 /* Misc Register */ -#define IMX2_WDT_MAX_TIME 128 +#define IMX2_WDT_MAX_TIME 128U #define IMX2_WDT_DEFAULT_TIME 60 /* in seconds */ #define WDOG_SEC_TO_COUNT(s) ((s * 2 - 1) << 8) @@ -180,7 +180,7 @@ static int imx2_wdt_set_timeout(struct watchdog_device *wdog, { unsigned int actual; - actual = min(new_timeout, wdog->max_hw_heartbeat_ms * 1000); + actual = min(new_timeout, IMX2_WDT_MAX_TIME); __imx2_wdt_set_timeout(wdog, actual); wdog->timeout = new_timeout; return 0; -- 2.20.1