Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18;
MIME-Version: 1.0
References: <20211007124858.44011-1-tony@atomide.com> <20211007124858.44011-2-tony@atomide.com>
 <CAMuHMdX3XBA25sUMF2SpfbH7XX5-UpPFj-0nHuwDOv49YWQn+A@mail.gmail.com> <YV8tZP05lAukFc4E@atomide.com>
In-Reply-To: <YV8tZP05lAukFc4E@atomide.com>
From:   Geert Uytterhoeven <geert@linux-m68k.org>
Date:   Thu, 7 Oct 2021 19:57:06 +0200
Message-ID: <CAMuHMdUzL7PWrUaO3CeCz7XXm=cmSg4BEZo582cxeTL_YuuETQ@mail.gmail.com>
Subject: Re: [PATCH 1/3] dt-bindings: bus: simple-pm-bus: Make clocks and
 power-domains optional
To:     Tony Lindgren <tony@atomide.com>
Cc:     Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        Rob Herring <robh+dt@kernel.org>,
        Linux ARM <linux-arm-kernel@lists.infradead.org>,
        "open list:OPEN FIRMWARE AND FLATTENED DEVICE TREE BINDINGS" 
        <devicetree@vger.kernel.org>,
        "open list:TI ETHERNET SWITCH DRIVER (CPSW)" 
        <linux-omap@vger.kernel.org>, Rob Herring <robh@kernel.org>,
        Simon Horman <horms+renesas@verge.net.au>,
        Suman Anna <s-anna@ti.com>
Content-Type: text/plain; charset="UTF-8"
Precedence: bulk

Hi Tony,

On Thu, Oct 7, 2021 at 7:24 PM Tony Lindgren <tony@atomide.com> wrote:
> * Geert Uytterhoeven <geert@linux-m68k.org> [211007 13:27]:
> > On Thu, Oct 7, 2021 at 2:49 PM Tony Lindgren <tony@atomide.com> 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.

Gr{oetje,eeting}s,

                        Geert

-- 
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

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