Messages in this thread | | | Subject | Re: [PATCH] watchdog: imx2_wdt: fix min() calculation in imx2_wdt_set_timeout | From | Guenter Roeck <> | Date | Mon, 12 Aug 2019 06:28:05 -0700 |
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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>
> --- > 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; >
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