Messages in this thread | | | Date | Wed, 19 Apr 2017 21:10:00 -0600 | From | Jens Axboe <> | Subject | Re: [PATCH 0/5] nvme APST fixes/improvements for 4.11 |
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On Wed, Apr 19 2017, Andy Lutomirski wrote: > Sorry for waiting so long for this. I was waiting for feedback from > Samsung, but they haven't root-caused the issue yet, and I should > have just done this from the beginning. > > This series makes APST more debuggable and updates the quirk list. > The quirks I'm aware of are: > > - Samsung 950 series SSDs in Dell XPS 15 9550 and Precision 5510 > laptops (which are essentially the same laptop) can lose their > PCIe link if they're allowed to use the deepest APST state. > Samsung engineers have an affected system and are working on > it. The same exact SSDs in other machines (even an XPS 13) > seem to work fine. > > - One Toshiba device malfunctions if APST is used at all.
You need to split this series in two, patches 1-3 can wait. For 4.11, all we need to do is turn off APST on any device that potentially has this problem.
> One thing that improves my confidence that there aren't too many > more problems with APST is that Ubuntu has backported APST to Zesty, > so it's already gotten a bit of testing in a widely used (if very > new) release.
Honestly, I think the best path for 4.11 is to turn off APST by default, make it opt-in instead. I don't share your optimism here, as I made clear back from before we even merged this feature.
-- Jens Axboe
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