Messages in this thread | | | Date | Fri, 14 Oct 2011 12:00:59 -0400 (EDT) | From | Alan Stern <> | Subject | Re: [RFC][PATCH 0/2] PM / Sleep: Extended control of suspend/hibernate interfaces |
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On Fri, 14 Oct 2011, NeilBrown wrote:
> Hi Rafael, > > What do you mean by "too complicated to use in practice"? What is you > measure for complexity? > Using suspend in a race-free way is certainly less complex than - for > example - configuring bluetooth. > And in what way is it "inadequate for other reasons"? What reasons? > > > The only sane way to handle suspend is for any (suitably privileged) process > to be able to request that suspend doesn't happen, and then for one process > to initiate suspend when no-one is blocking it.
One of the things Rafael didn't mention is that sometimes a kernel driver needs to prevent the system from suspending. This happens when recharging over a USB connection.
There's no simple way for such a driver to communicate with a power daemon. The driver has to use something like the wakeup mechanism -- but currently that mechanism is optional.
Alan Stern
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