ACK/cmnt: [Resend] [SRU] [B/C/D/Unstable] [PATCH 0/2] Power consumption during s2idle is higher than long idle (Intel SSDPEKKF)

[Kleber Souza]

On 11/22/18 8:15 AM, Kai-Heng Feng wrote:
> BugLink: https://bugs.launchpad.net/bugs/1804588
>
> [Impact]
> On new systems that facilitate s2idle, we observed the power consumption
> raises higher than long idle does during s2idle with Intel NVMe
> SSDPEKKF.
>
> Short idle: 6
> Long idle: 2
> S2I: 4.8
>
> [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 new Intel NVMe, it fixes the power consumption issue
> with no regression. And the power consumption decreases to 2.8W during
> s2idle.
>
> [Regression Potential]
> Low, the patches only applied to specific nvme module, and from our
> test, the system is still stable.
>
> Kai-Heng Feng (2):
>   SAUCE: pci: prevent Intel NVMe SSDPEKKF from entering D3
>   SAUCE: nvme: add quirk to not call disable function when suspending
>
>  drivers/nvme/host/pci.c | 2 ++
>  drivers/pci/quirks.c    | 1 +
>  2 files changed, 3 insertions(+)
>
Note that the correct tag for sauce patches are "UBUNTU: SAUCE:" instead
of just "SAUCE:". This can be fixed when applying the patches.


Acked-by: Kleber Sacilotto de Souza <kleber.souza at canonical.com>