Hi,

On 08/03/2015 at 02:12:53 +0100, Rafael J. Wysocki wrote :

quoted

quoted

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.

Well, it boils down to "what is stronger". Desire to suspend the
system, or desire to reboot the system.

It is "echo mem > state", not "echo reboot > state".

quoted

It is documented in the datasheet and any user wanting another behaviour
is out of luck.

Actaully, your platform should just refuse to enter suspend-to-RAM
when hw watchdog is enabled.

Quite likely, depending on how exactly the suspend is implemented.

We've had absolutely zero complain on that. It is quite clear in the
datasheet that failing to refresh the watchdog once started will lead to
a reset and that it is impossible to stop.
It is actually quite convenient to also ensure that you can actually
wake up from suspend because that can obviously go wrong.

-- 
Alexandre Belloni, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com