at91sam9: watchdog: period

Jiří Prchal jiri.prchal at
Tue May 19 02:52:16 PDT 2015

On 19.5.2015 11:14, Boris Brezillon wrote:
> There's a difference between your heartbeat (the frequency you
> refresh/reset your watchdog) and the watchdog expiration time (here set
> to 16 secs).
> We usually set the heartbeat to 1/2 or 1/4 the expiration time, so that
> we're (almost) sure we can reset the watchdog before its expiration.
I'm confused. Why need kernel to know the time in witch userspace process will reset watchdog?
And how to change watchdog expiration time?

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