On 8/12/19 6:13 AM, Rasmus Villemoes wrote:

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@vger.kernel.org # 5.2 plus anything the above got backported to Signed-off-by: Rasmus Villemoes linux@rasmusvillemoes.dk

Reviewed-by: Guenter Roeck linux@roeck-us.net

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This should really be handled in the watchdog core for any driver that reports max_hw_heartbeat_ms.

Good point. I'll see if I can write a patch.

Guenter

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;