| Message ID | 20190812131356.23039-1-linux@rasmusvillemoes.dk (mailing list archive) |
|---|---|
| State | Accepted |
| Headers | show |
| Series | watchdog: imx2_wdt: fix min() calculation in imx2_wdt_set_timeout | expand |
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; >
On 12/08/2019 15.28, Guenter Roeck wrote: > 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> I'm not seeing this in v5.3-rc6, did it get picked up? Rasmus
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;
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> --- 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(-)