Re: [PATCH 05/12] PCI: aardvark: add suspend to RAM support

From: Rafael J. Wysocki
Date: Thu Dec 13 2018 - 16:51:17 EST


On Thursday, December 13, 2018 3:30:00 PM CET Miquel Raynal wrote:
> Hi Lorenzo,
>
> > > If that's really the case, then I can see how one device and it's
> > > children are suspended and the irq for it is disabled but the providing
> > > devices (clk, regulator, bus controller, etc.) are still fully active
> > > and not suspended but in fact completely usable and able to service
> > > interrupts. If that all makes sense, then I would answer the question
> > > with a definitive "yes it's all fine" because the clk consumer could be
> > > in the NOIRQ phase of its suspend but the clk provider wouldn't have
> > > even started suspending yet when clk_disable_unprepare() is called.
> >
> > That's a very good summary and address my concern, I still question this
> > patch correctness (and many others that carry out clk operations in S2R
> > NOIRQ phase), they may work but do not tell me they are rock solid given
> > your accurate summary above.
>
> I understand your concern but I don't see any alternative right now
> and a deep rework of the PM core to respect such dependency is not
> something that can be done in a reasonable amount of time.

Maybe you don't need to rework anything. :-)

Have you considered using device links?

Thanks,
Rafael