On 22/02/17 14:50, Rafael J. Wysocki wrote: > On Wed, Feb 22, 2017 at 3:32 PM, Sudeep Holla <sudeep.ho...@arm.com> wrote:
[...] >> >> OK, I thought I had told this before. What do you mean by PSCI system >> suspend can't wakeup from the configured wakeup source. You just said >> above that you can wake up from the switch. >> >> Just enabling the wakeup sources in Linux doesn't mean you can enter >> system suspend anytime. You must enter only the state from which you can >> resume. And in your case if you can't wakeup from WLAN or wakeup source >> you have configured then simply don't enter system suspend. > > Well, not quite. > > The sysfs wakeup setting for devices only means whether or not to > enable the generation of wakeup signals for them while suspending. It > allows to *prevent* devices from waking up the system, but it doesn't > guarantee that they will actually wake up if enabled. > > Now, the platform doesn't decide on the sleep state it will go to on > the basis of what devices have been enabled to wake up the system. > The states ("shallow", "deep") have to be defined upfront, including > what devices can wake up from the "shallow" and what devices can wake > up from the "deep" states (these lists need not be the same). [As I > said before, the assumption is that all of them will be able to wake > up the system from suspend-to-idle.] > > So, if user space triggers a transition to the "shallow" state, say, > it will be possible to wake up the system from it by devices that (a) > can wake it up from the "shallow" state as defined for the given > platform and (b) have been enabled to wake up the system via sysfs. > > Conversely, if you have a system power state such that only a subset > of devices can wake up from it, it needs to be defined as either > "shallow" or "deep" and the list of possible wakeup sources is part of > that definition. Completely agreed. And yes the current assumption is that the set of wake-up source in DT applies to the suspend-to-idle case and may/may not from the deeper s2ram state. Sorry if I conveyed something else in my emails. I was mostly referring to the patch set and the way it's hacking up. I still fail to understand what Geert is doing different in his "shallow" state that "s2idle" can't achieve that state. So my comments were more aligned to that when I made the above comment. -- Regards, Sudeep