On 07/03/2015 at 11:39:39 +0100, Pavel Machek wrote : > > The Atmel watchdog can't be stopped once it's started. This is actually > > very useful so we can reset if suspend or resume failed, the only > > drawback is that you have to wake up from time to time (e.g. by using > > the RTC/RTT) to clear the watchdog and then go back to sleep ASAP. > > Yeah. So you do "echo mem > /sys/power/state", and few seconds/minutes > after watchdog kills the system. But you did not ask for dead system, > you asked for suspend. > > And while that behaviour is useful for you, I don't think it is > exactly useful behaviour, nor it is the behaviour user would expect. > I think you misunderstood, that is exactly the expected behaviour. This is hardware defined. Once the watchdog is started, nobody can stop it. Trying to change the mode register will result in a reset of the SoC. It is documented in the datasheet and any user wanting another behaviour is out of luck. So basically, when using a watchdog, you have to wake up every 15-16s to restart it. -- Alexandre Belloni, Free Electrons Embedded Linux, Kernel and Android engineering http://free-electrons.com -- To unsubscribe from this list: send the line "unsubscribe linux-serial" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
