Re: Waking from suspend

[Patrick O'Callaghan]

On Sun, 2024-08-25 at 20:09 -0700, Samuel Sieb wrote:
> On 8/25/24 12:51 AM, Barry wrote:
> > > On 24 Aug 2024, at 12:18, Patrick O'Callaghan
> > >  wrote:
> > >
> > > If the RTC can wake
> > > the system from hibernation, why can't it wake it from
> > > suspension?
> >
> > The RTC wake powers on the system. But a suspended system is
> > already powered up and kernel is in charge.
>
> Sort of.  It's no longer running and the BIOS/UEFI is in charge of
> wakeup.
> > You need to use a systemd timer to schedule the wake up.
>
> Again, sort of.  If the wakeup option is set, it will set the HW RTC
> to trigger a wakeup so it can run.

Currently I do this by writing directly to
/sys/class/rtc/rtc0/wakealarm. Are you saying there's a way to get
systemd to do that for me?

poc