Re: [PATCH net-next 2/3] sh_eth: Convert to DEFINE_SIMPLE_DEV_PM_OPS()

On Mon, 8 Sept 2025 at 16:36, Geert Uytterhoeven <[email protected]> wrote:
> On Fri, 5 Sept 2025 at 20:41, Niklas Söderlund
> <[email protected]> wrote:
> > On 2025-09-05 13:57:05 +0200, Andrew Lunn wrote:
> > > > You cannot enter system sleep without CONFIG_PM_SLEEP, so enabling
> > > > WoL would be pointless.
> > >
> > > Yet get_wol will return WoL can be used, and set_wol will allow you to
> > > configure it. It seems like EOPNOTSUPP would be better.
> >
> > Out of curiosity. Are you suggesting a compile time check/construct for
> > CONFIG_PM_SLEEP be added in the driver itself, or in ethtool_set_wol()
> > and ethtool_get_wol() in net/ethtool/ioctl.c to complement the
> >
> >     if (!dev->ethtool_ops->get_wol || !dev->ethtool_ops->set_wol)
> >         return -EOPNOTSUPP;
> >
> > checks already there? To always return EOPNOTSUPP if PM_SLEEP is not
> > selected?
>
> Iff we want to go that route, I'd vote for handling it in common code.
> Still, there is no guarantee that WoL will actually work, as on
> some systems it may depend on the firmware, too.  E.g. on ARM
> systems with PSCI, the SoC may be powered down during s2ram, so
> there is no guarantee that any of the wake-up sources shown in
> /sys/kernel/debug/wakeup_sources can actually wake up the system.
> I tried having a mechanism to describe that in DT, but it was rejected.

(oops, forgot to press "send" in an old draft)

Discovering commit af8dbf9c6aa8972f ("schemas: wakeup-source:
Possibility for system states") in dt-schema.git, there seems to
be hope!

Gr{oetje,eeting}s,

                        Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- [email protected]

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds