Re: [Regression] Commit "nvme/pci: Use host managed power state for suspend" has problems

Keith Busch
2019-07-31T22:22:41Z

On Wed, Jul 31, 2019 at 11:25:51PM +0200, Rafael J. Wysocki wrote:
>
> A couple of remarks if you will.
>
> First, we don't know which case is the majority at this point. For
> now, there is one example of each, but it may very well turn out that
> the SK Hynix BC501 above needs to be quirked.
>
> Second, the reference here really is 5.2, so if there are any systems
> that are not better off with 5.3-rc than they were with 5.2, well, we
> have not made progress. However, if there are systems that are worse
> off with 5.3, that's bad. In the face of the latest findings the only
> way to avoid that is to be backwards compatible with 5.2 and that's
> where my patch is going. That cannot be achieved by quirking all
> cases that are reported as "bad", because there still may be
> unreported ones.

I have to agree. I think your proposal may allow PCI D3cold, in which
case we do need to reintroduce the HMB handling.