Re: [RFC PATCH] PM / core: skip suspend next time if resume returns an error

[Pavel Machek]

Hi!

> In general Linux doesn't behave super great if you get an error while
> executing a device's resume handler.  Nothing will come along later
> and and try again to resume the device (and all devices that depend on
> it), so pretty much you're left with a non-functioning device and
> that's not good.
> 
> However, even though you'll end up with a non-functioning device we
> still don't consider resume failures to be fatal to the system.  We'll
> keep chugging along and just hope that the device that failed to
> resume wasn't too critical.  This establishes the precedent that we
> should at least try our best not to fully bork the system after a
> resume failure.
> 
> I will argue that the best way to keep the system in the best shape is
> to assume that if a resume callback failed that it did as close to
> no-op as possible.  Because of this we should consider the device
> still suspended and shouldn't try to suspend the device again next
> time around.  Today that's not what happens.  AKA if you have a
> device

I don't think there are many guarantees when device resume fail. It
may have done nothing, and it may have resumed the device almost
fully.

I guess the best option would be to refuse system suspend after some
device failed like that.

That leaves user possibility to debug it...

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

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