Re: [RFD] Automatic suspend

Rafael J. Wysocki
2009-02-21T20:20:35Z

On Saturday 21 February 2009, Arve Hjønnevåg wrote:
> On Sat, Feb 21, 2009 at 1:47 AM, Rafael J. Wysocki <rjw@sisk.pl> wrote:
> > On Saturday 21 February 2009, Arve Hjønnevåg wrote:
> >> On Fri, Feb 20, 2009 at 3:57 PM, Rafael J. Wysocki <rjw@sisk.pl> wrote:
> >> > On Saturday 21 February 2009, Arve Hjønnevåg wrote:
> >> >> On Fri, Feb 20, 2009 at 7:56 AM, Rafael J. Wysocki <rjw@sisk.pl> wrote:
> >> >> > On Friday 20 February 2009, Arve Hjønnevåg wrote:
> >> >> >> On Fri, Feb 20, 2009 at 2:49 AM, Rafael J. Wysocki <rjw@sisk.pl> wrote:
> >> >> >> > On Friday 20 February 2009, Arve Hjønnevåg wrote:
> >> >> >> >> On Thu, Feb 19, 2009 at 2:08 PM, Alan Stern <stern@rowland.harvard.edu> wrote:
[--snip--]
> >> > The idea is to have both /sys/power/state and /sys/power/sleep at the same
> >> > time, where /sys/power/state will work just like it does right now. Sure,
> >> > there must be mutual exclusion between the two, but that's a matter of
> >> > implementation IMO.
> >>
> >> If you want to only prevent suspend though one interface, you have to
> >> also pass information to the driver about its suspend hook is being
> >> called so it can conditionally return -EBUSY. The wakelock interface
> >> requires less code in each driver.
> >
> > Well, I don't think so. Moreover, it requires you to spread wakelocks all
> > over the place if you don't use the timeouted ones which, let's face it, is
> > hardly acceptable.
>
> Your method does not reduce the number of places that has to be
> modified. Any component where we add a wakelock, you have to add a
> suspend handler to abort suspend when we would have held a wakelock.

Well, maybe not, but it doesn't introduce entirely new API for device drivers.
Instead, it extends the existing interfaces which I think is more appropriate.

Thanks,
Rafael