Fwd: [Bug 196907] [Regression] New default s2idle does not work on Dell XPS 13 9360 with Ubuntu 16.04.3 LTS (Xenial Xerus)

[Rafael J. Wysocki]

On Tuesday, October 10, 2017 12:14:14 AM CEST Keith Busch wrote:
> On Mon, Oct 09, 2017 at 11:52:26PM +0200, Rafael J. Wysocki wrote:
> > Hi,
> > 
> > We are seeing a resume issue with a Hynix SSD (PC300 NVMe SK hynix 512GB)
> > with respect to suspend-to-idle (S3 resume works for the reporter,
> > interestingly enough).  It appears to be limited to Hynix and to that
> > specific SSD ATM.
> > 
> > Also it is reported to work in 4.11-rc1 and it already is failing in 4.13,
> > so it looks like something between the two broke it.
> > 
> > Any ideas of what that might be?
> > 
> > Or anything we should try/test to narrow it down?
> > 
> > Any help will be appreciated.
> 
> I'd start with the APST feature and see if disabling that helps.
> That can be done with the nvme_core module param:
> 
>   default_ps_max_latency_us=0
> 

We've tried that and it doesn't help.