Messages in this thread Patch in this message | | | Subject | Re: [PATCH v1] watchdog: sama5d4_wdt: Reset delay on start | From | "Yang, Wenyou" <> | Date | Fri, 4 Mar 2016 09:35:05 +0800 |
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Hi Romain,
On 2016/3/3 18:29, Romain Izard wrote: > If the internal counter is not refreshed when the watchdog is started > for the first time, the watchdog will trigger very rapidly. For example, > opening /dev/watchdog without writing in it will immediately trigger a > reboot, instead of waiting for the delay to expire. > > To avoid this problem, reload the timer on opening the watchdog device. > > Command: "while sleep 5; do echo 1; done > /dev/watchdog" > Before: system reset > After: the watchdog runs correctly I didn't reproduce your issue on my side,
run the your commands as follows, it works fine, the system reset doesn't happen. ---8<---- #!/bin/sh
while [ 1 ] do sleep 5; echo 1 > /dev/watchdog done --->8----
I also check the WDT_MR register before and after enabling watchdog, the WDV and WDD fields are correct.
Can you check it again? thank you.
> > Signed-off-by: Romain Izard <romain.izard.pro@gmail.com> > --- > drivers/watchdog/sama5d4_wdt.c | 3 +++ > 1 file changed, 3 insertions(+) > > diff --git a/drivers/watchdog/sama5d4_wdt.c b/drivers/watchdog/sama5d4_wdt.c > index a49634cdc1cc..e162fe140ae1 100644 > --- a/drivers/watchdog/sama5d4_wdt.c > +++ b/drivers/watchdog/sama5d4_wdt.c > @@ -15,6 +15,7 @@ > #include <linux/platform_device.h> > #include <linux/reboot.h> > #include <linux/watchdog.h> > +#include <linux/delay.h> > > #include "at91sam9_wdt.h" > > @@ -58,6 +59,8 @@ static int sama5d4_wdt_start(struct watchdog_device *wdd) > reg = wdt_read(wdt, AT91_WDT_MR); > reg &= ~AT91_WDT_WDDIS; > wdt_write(wdt, AT91_WDT_MR, reg); > + udelay(125); /* > 4 cycles at 32,768 Hz */ > + wdt_write(wdt, AT91_WDT_CR, AT91_WDT_KEY | AT91_WDT_WDRSTT); > > return 0; > }
Best Regards, Wenyou Yang
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