APPLIED(B,C): [PATCH 0/1][SRU][B][C][D][OEM-B]PC SN720 NVMe WDC 256GB consumes more power in S2Idle than during long idle

[AceLan Kao]

Stefan Bader <stefan.bader at canonical.com> 於 2019年1月8日 週二 下午7:29寫道：
>
> On 08.01.19 07:03, Khaled Elmously wrote:
> > On 2018-11-29 15:44:23 , AceLan Kao wrote:
> >> To avoid conflicts, this patch assumes below commits have been applied
> >> on top of master-next branch on Bionic, Cosmic, and Disco kernel,
> >> since both patches modify the same files on the same position for the
> >> same issue.
> >> https://lists.ubuntu.com/archives/kernel-team/2018-November/096832.html
> >>
> >> BugLink: https://bugs.launchpad.net/bugs/1805775
>
> Bug report did not reflect the applied state. Actually it was in rather bad shape:
>
> 1. No task for the linux source (no nominations for bionic and cosmic there)
> 2. Nomination for bionic/linux-oem not accepted.
I'll check more careful next time.

>
> >>
> >> [Impact]
> >> On new systems that facilitate s2idle, we observed the power consumption
> >> raises higher than long idle does during s2idle with Western Digital PC
> >> SN720 NVMe SSD SDAPNTW-256G.
> >>
> >> Short idle: 5.3
> >> Long idle: 3.0
> >> S2I: 5.07
> >>
> >> [Fix]
> >> Windows doesn't put nvme to D3 in modern standby, and uses its own APST
> >> feature to do the power management. To leverage its APST feature during
> >> s2idle, we can't disable nvme device while suspending, too.
> >> So, here is what we did on the driver, 1. prevent nvme from entering D3,
> >> 2. prevent nvme from being disabled when suspending.
> >>
> >> [Test]
> >> Verified on the WD NVMe, it fixes the power consumption issue with no
> >> regression. And the power consumption decreases to 1.66W during s2idle.
> >>
> >> [Regression Potential]
> >> Low, the patches only applied to specific nvme module, and from our test,
> >> the system is still stable.
> >>
> >> AceLan Kao (1):
> >>   SAUCE: pci/nvme: prevent WDC PC SN720 NVMe from entering D3 and being
> >>     disabled
> >>
> >>  drivers/nvme/host/pci.c | 2 ++
> >>  drivers/pci/quirks.c    | 1 +
> >>  2 files changed, 3 insertions(+)
> >>
> >> --
> >> 2.17.1
> >>
> >>
> >> --
> >> kernel-team mailing list
> >> kernel-team at lists.ubuntu.com
> >> https://lists.ubuntu.com/mailman/listinfo/kernel-team
> >
>
>