From: "Rafael J. Wysocki" <rafael@kernel.org>
To: Kai-Heng Feng <kai.heng.feng@canonical.com>
Cc: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>,
Linux PM <linux-pm@vger.kernel.org>,
"open list:LIBATA SUBSYSTEM (Serial and Parallel ATA drivers)"
<linux-ide@vger.kernel.org>,
open list <linux-kernel@vger.kernel.org>,
Kent Lin <kent.lin@canonical.com>, Tejun Heo <tj@kernel.org>
Subject: Re: Hard Disk consumes lots of power in s2idle
Date: Thu, 20 Feb 2020 11:12:18 +0100 [thread overview]
Message-ID: <CAJZ5v0jXvo0ceNMp=kstTi24Ne7F-ZGMcD0T0TSMpcZZWsJsUA@mail.gmail.com> (raw)
In-Reply-To: <235CF4F8-19BF-4B00-8C92-E59CB2D476A7@canonical.com>
On Thu, Feb 20, 2020 at 9:08 AM Kai-Heng Feng
<kai.heng.feng@canonical.com> wrote:
>
> Hi Srinivas,
>
> > On Feb 20, 2020, at 02:36, Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com> wrote:
> >
> > Hi Kai,
> >
> > On Wed, 2020-02-19 at 22:22 +0800, Kai-Heng Feng wrote:
> >> Hi Srinivas,
> >>
> >> Your previous work to support DEVSLP works well on SATA SSDs, so I am
> >> asking you the issue I am facing:
> >> Once a laptop has a HDD installed, the power consumption during
> >> S2Idle increases ~0.4W, which is quite a lot.
> >> However, HDDs don't seem to support DEVSLP, so I wonder if you know
> >> to do proper power management for HDDs?
> > What is the default here
> > cat /sys/power/mem_sleep
> > s2idle or deep?
>
> It defaults to s2idle.
>
> >
> > Please follow debug steps here:
> > https://01.org/blogs/qwang59/2018/how-achieve-s0ix-states-linux
> >
> > We need to check whether you get any PC10 residency or not.
>
> Yes it reaches PC10. It doesn't reach SLP_S0 though.
> The real number on S2Idle power consumption:
> No HDD: ~1.4W
> One HDD: ~1.8W
>
> If the SoC doesn't hit PC10 the number should be significantly higher.
> That's why I think the issue is the power management on HDD itself.
I'm assuming that you mean a non-SSD device here.
That would be handled via ata_port_suspend() I gather and whatever
that does should do the right thing.
Do you think that the disk doesn't spin down or it spins down, but the
logic stays on?
next prev parent reply other threads:[~2020-02-20 10:12 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-02-19 14:22 Hard Disk consumes lots of power in s2idle Kai-Heng Feng
2020-02-19 18:36 ` Srinivas Pandruvada
2020-02-20 8:08 ` Kai-Heng Feng
2020-02-20 10:12 ` Rafael J. Wysocki [this message]
2020-02-20 10:24 ` Kai-Heng Feng
2020-02-20 10:34 ` Rafael J. Wysocki
2020-02-20 11:21 ` Kai-Heng Feng
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