Re: [PATCH] serial: 8250_omap: Set the console genpd always on if no console suspend

[Tony Lindgren <tony@atomide.com>]

* Kevin Hilman <khilman@kernel.org> [231128 04:52]:
> Tony Lindgren <tony@atomide.com> writes:
> 
> > * Kevin Hilman <khilman@kernel.org> [231128 04:05]:
> >> Tony Lindgren <tony@atomide.com> writes:
> >> 
> >> > * Théo Lebrun <theo.lebrun@bootlin.com> [231124 10:39]:
> >> >> On Fri Nov 24, 2023 at 6:37 AM CET, Tony Lindgren wrote:
> >> >> Checking the code confirms this behavior. Grep for the macro
> >> >> genpd_is_active_wakeup rather than GENPD_FLAG_ACTIVE_WAKEUP. It gets
> >> >> used twice (suspend & resume), both in the same manner:
> >> >> 
> >> >>    if (device_wakeup_path(dev) && genpd_is_active_wakeup(genpd))
> >> >> 
> >> >> This means this flag won't have any impact on runtime PM handling of
> >> >> power-domains. By the way, other users of the flag enable it at PD
> >> >> registration & don't touch it afterwards.
> >> >
> >> > Setting GENPD_FLAG_ACTIVE_WAKEUP will block deeper idle states for
> >> > the SoC most likely.
> >> 
> >> It doesn't affect idle states.  It only affects suspend states.
> >> 
> >> As Théo pointed out, system-wide suspend will ignores runtime PM
> >> refcounts, so IMO, using this flag is the right approach.
> >
> > But it still blocks the deeper SoC suspend states if set, right?
> >
> > If so, it should be dynamically toggled depending on the console_suspend
> > flag.
> 
> Agreed, and that's what I think Théo proposed earlier in this thread[1].
> 
> Since the deeper suspend states are prevented only when this flag is
> present *and* the wakeup path is set, Théo's example just toggles the
> wakeup path set based on console_suspend_enabled.

Ah it's the *and* part I was missing! Yes great, that sounds good to
me.

Thanks,

Tony

> [1] https://lore.kernel.org/r/CX5F88JLWFUW.Z36KQB2PX554@tleb-bootlin-xps13-01