On Sat 2015-03-07 11:20:56, Sylvain Rochet wrote:

Hello,

On Sat, Mar 07, 2015 at 10:18:46AM +0100, Peter Zijlstra wrote:

quoted

On Thu, Mar 05, 2015 at 11:53:08AM +0000, Mark Rutland wrote:

quoted

If everyone else is happy with this using IRQF_NO_SUSPEND for now then
don't let my comments above block this patch.

Yeah, I'm really not happy with NO_SUSPEND + enable_irq_wake().

I really want that combo to BUG/WARN -- esp. since there's so much cargo
culted crap out there.

We should make robust interfaces, not randomly toggle flags until it
mostly works by accident rather than by design -- which is what this
feels like.

And while I appreciate the watchdog use-case; I think the easiest
solution for now is to simply disable the wathdog over suspend until
we've come up with something that makes sense.

As it is, you need to 'suspend' the watchdog at some point anyhow; you
don't want that thing to wake you from whatever suspend state you're in.

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.

									Pavel
-- 
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html