Re: [PATCH 1/3] dt-bindings: bus: simple-pm-bus: Make clocks and power-domains optional

From: Tony Lindgren
Date: Thu Oct 07 2021 - 14:17:21 EST


* Geert Uytterhoeven <geert@xxxxxxxxxxxxxx> [211007 17:57]:
> Hi Tony,
>
> On Thu, Oct 7, 2021 at 7:24 PM Tony Lindgren <tony@xxxxxxxxxxx> wrote:
> > * Geert Uytterhoeven <geert@xxxxxxxxxxxxxx> [211007 13:27]:
> > > On Thu, Oct 7, 2021 at 2:49 PM Tony Lindgren <tony@xxxxxxxxxxx> wrote:
> > > > Even without clocks and power domains configured, simple-pm-bus is still
> > > > different from simple-bus as simple-pm-bus enables runtime PM for the bus
> > > > driver.
> > >
> > > Which you need to have working Runtime PM for child devices, right? ;-)
> >
> > Right. And based on what I remember we simply cannot do pm_runtime_enable()
> > for simple-bus without breaking tons of devices.
>
> Why not? Do you have an example of what would break?
> The only reason I created simple-pm-bus was because the DT people
> objected to adding PM to simple-bus, as they considered it wrong
> conceptually. AFAIK this wouldn't have caused any actual breakage.

Oh OK, then I just remember the reasons wrong for the need for
adding it as a driver.

Regards,

Tony