Re: [PATCH v2 01/11] xen/manage: keep track of the on-going suspend mode

["Rafael J. Wysocki" <rafael@xxxxxxxxxx>]

On Fri, Jul 31, 2020 at 4:14 PM Boris Ostrovsky
<boris.ostrovsky@xxxxxxxxxx> wrote:
>
> On 7/30/20 7:06 PM, Anchal Agarwal wrote:
> > On Mon, Jul 27, 2020 at 06:08:29PM -0400, Boris Ostrovsky wrote:
> >> CAUTION: This email originated from outside of the organization. Do not 
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> >>
> >>
> >>
> >> On 7/24/20 7:01 PM, Stefano Stabellini wrote:
> >>> Yes, it does, thank you. I'd rather not introduce unknown regressions so
> >>> I would recommend to add an arch-specific check on registering
> >>> freeze/thaw/restore handlers. Maybe something like the following:
> >>>
> >>> #ifdef CONFIG_X86
> >>>     .freeze = blkfront_freeze,
> >>>     .thaw = blkfront_restore,
> >>>     .restore = blkfront_restore
> >>> #endif
> >>>
> >>>
> >>> maybe Boris has a better suggestion on how to do it
> >>
> >> An alternative might be to still install pm notifier in
> >> drivers/xen/manage.c (I think as result of latest discussions we decided
> >> we won't need it) and return -ENOTSUPP for ARM for
> >> PM_HIBERNATION_PREPARE and friends. Would that work?
> >>
> > I think the question here is for registering driver specific 
> > freeze/thaw/restore
> > callbacks for x86 only. I have dropped the pm_notifier in the v3 still 
> > pending
> > testing. So I think just registering driver specific callbacks for x86 only 
> > is a
> > good option. What do you think?
>
>
> I suggested using the notifier under assumption that if it returns an
> error then that will prevent callbacks to be called because hibernation
> will be effectively disabled.

That's correct.