[SRU] [Xenial] [PATCH 00/10] Enable NVMe APST for Xenial

[Seth Forshee]

On Fri, Apr 28, 2017 at 12:20:12PM +0800, Kai-Heng Feng wrote:
> BugLink: https://bugs.launchpad.net/bugs/1664602
> 
> Impact:
> NVME APST feature is not enabled, so the power consumption is higher. We
> already did that for Yakkety and Zesty. After upstream adjusted a new quirk for
> XPS 9550 and Precision 5510, I think it's time to make it into Xenial.
> 
> Fix:
> Enable NVME APST to conserve energy.
> 
> Test:
> Use 'nvme get-feature -f 0x0c -H /dev/nvme0' from nvme-cli to query the feature.
> 
> Before APST enabled:
> get-feature:0xc (Autonomous Power State Transition), Current value:00000000
>         Autonomous Power State Transition Enable (APSTE): Disabled
> 
> After APST enabled:
> get-feature:0xc (Autonomous Power State Transition), Current value:0x000001
>         Autonomous Power State Transition Enable (APSTE): Enabled
> 
> In addition, with the new quirk, the deepest power state is disabled on Precision
> 5510 & Samsung NVMe. I verified this via `nvme get-feature -f 0x0c -H /dev/nvme0`.
> 
> Last two commits 'nvme: Adjust the Samsung APST quirk' and
> 'nvme: Quirk APST off on "THNSF5256GPUK TOSHIBA"' are from Jen Axboe's block tree.

Aren't there some other drives which are still known to need quirks,
i.e. LP #1686592? I think we need to hold off on enabling APST until we
have quirks for all drives which are known to have problems with it.

Seth