Re: A desktop environment[1] kernel wishlist

Bastien Nocera
2014-10-30T14:45:52Z

On Wed, 2014-10-29 at 22:16 +0100, Pavel Machek wrote:
> On Wed 2014-10-29 16:26:16, Theodore Ts'o wrote:
> > On Wed, Oct 29, 2014 at 12:19:56PM -0700, Andy Lutomirski wrote:
> > > For a tablet, isn't the relevant piece of information whether the power
> > > button was recently pressed, not whether the power button caused the wakeup?
> >
> > For Android L devices, it has been reported that the device might
> > power up its screen fully (note I didn't say 'wake up') automatically
> > when it detects that you are picking it up, or when you double-tap the
> > screen. It also reportedly has a low power black and white "ambient
> > display" (ala the Android Wear devics) which allows you to see
> > notifications without waking up the phone all the way[1]. (All of
> > this assuming appropriate hardware support, of course.)
> >
> > [1] http://www.androidauthority.com/ambient-display-lollipop-541198/
> >
> > Which goes back to the concept of having a "suspend" mode is legacy
> > thinking. Modern devices will soon have not just a "awake" and a
> > "asleep" modes; there will be (well, is now) a much wider spectrum of
> > modes, with the goal of using the minimum amount of power while still
> > providing use functionality to the user.
>
> Actually Maemo people (on Nokia N900 and friends) got it right: unlike
> android devices, it does not suspend to RAM at any point, and still
> has reasonable battery life.

Android devices don't suspend to RAM. Neither do Tizen devices AFAIK.

> So I agree -- using suspend to RAM on "active" cell phone is just a
> bad design.

I don't think anyone was discussing cell phones in particular in this
thread, and knowing when user-space got woken up because of the baseband
processor having information for us would still be useful.