Re: [PATCH] nvme-pci: Shutdown the device if D3Cold is allowed by the user

Rafael J. Wysocki
2024-12-13T14:35:30Z

On Thu, Dec 12, 2024 at 4:14 PM Christoph Hellwig <hch@lst.de> wrote:
>
> On Thu, Dec 12, 2024 at 01:49:15PM +0100, Ulf Hansson wrote:
> > Right. This seems to somewhat work for ACPI types of systems, because
> > ACPI is controlling the low power state for all the devices. Based on
> > the requested system wide low power state, ACPI can then decide to
> > call pm_set_suspend_via_firmware() or not.
> >
> > Still there is a problem with this for ACPI too.
> >
> > How does ACPI know whether it's actually a good idea to keep the NVMe
> > storage powered in s2idle (ACPI calls pm_set_suspend_via_firmware()
> > only for S2R and S2disk!?)? Especially when my laptop only supports
> > s2idle and that's what I will use when I close the lid. In this way,
> > the NMVe storage will certainly contribute to draining the battery,
> > especially when I won't be using my laptop for a couple of days.
> >
> > In my opinion, we need a better approach that is both flexible and
> > that dynamically adjusts based upon the use case.
>
> Agreed. I'd be happy to work with the PM maintainers to do this,
> but I don't really know enough about the PM core to drive it
> (as the reply from Rafael to my mail makes pretty clear :))

I'm here to help.

Let me know what exactly you want to achieve and we'll see how to make it work.