Re: [PATCH] component: Move host device to end of device lists on binding

[Rafael J. Wysocki]

On Mon, May 10, 2021 at 9:08 PM Stephen Boyd <swboyd@xxxxxxxxxxxx> wrote:

[cut]

>
> >
> > > I will try it, but then I wonder about things like system wide
> > > suspend/resume too. The drm encoder chain would need to reimplement the
> > > logic for system wide suspend/resume so that any PM ops attached to the
> > > msm device run in the correct order. Right now the bridge PM ops will
> > > run, the i2c bus PM ops will run, and then the msm PM ops will run.
> > > After this change, the msm PM ops will run, the bridge PM ops will run,
> > > and then the i2c bus PM ops will run. It feels like that could be a
> > > problem if we're suspending the DSI encoder while the bridge is still
> > > active.
> >
> > Yup suspend/resume has the exact same problem as shutdown.
>
> I think suspend/resume has the exact opposite problem. At least I think
> the correct order is to suspend the bridge, then the encoder, i.e. DSI,
> like is happening today. It looks like drm_atomic_helper_shutdown()
> operates from the top down when we want bottom up? I admit I have no
> idea what is supposed to happen here.

Why would the system-wide suspend ordering be different from the
shutdown ordering?