linux-kernel - Re: [PATCH] ACPI / sleep: EC-based wakeup from suspend-to-idle on recent systems

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Message-ID: <CA+b4Kqd5qO2Q6drnfvhCyj_q33Hjg1nT7vbgm-uoc+wjpX=e3Q@mail.gmail.com>
Date:   Thu, 6 Jul 2017 21:41:36 +1000
From:   Tom Lanyon <tom@...shoeco.com>
To:     Srinivas Pandruvada <srinivas.pandruvada@...ux.intel.com>
Cc:     "Rafael J. Wysocki" <rjw@...ysocki.net>,
        Linux ACPI <linux-acpi@...r.kernel.org>,
        Linux PM <linux-pm@...r.kernel.org>,
        Andy Shevchenko <andriy.shevchenko@...ux.intel.com>,
        Darren Hart <dvhart@...radead.org>,
        LKML <linux-kernel@...r.kernel.org>,
        Mika Westerberg <mika.westerberg@...ux.intel.com>,
        Mario Limonciello <mario.limonciello@...l.com>,
        Jérôme de Bretagne 
        <jerome.debretagne@...il.com>, "Zheng, Lv" <lv.zheng@...el.com>,
        Linus Torvalds <torvalds@...ux-foundation.org>
Subject: Re: [PATCH] ACPI / sleep: EC-based wakeup from suspend-to-idle on
 recent systems

Sorry for the slow response - I've just had a chance to run some more tests.

I tried to disable the SD card reader in the BIOS as suggested earlier
in the thread, but that didn't seem to make a significant change.
More inline below.

On Tue, 2017-06-27 at 17:03 +0200, Rafael J. Wysocki wrote:
> I would carry out s2idle under turbostat to see how much PC10
> residency is there while suspended.  That may be a significant factor.
>
> Most likely there is a device preventing the SoC from reaching its
> deepest low-power states under Linux on your system and it needs to be
> identified and dealt with.

I'm not entirely sure how turbostat records metrics so wasn't sure how
to measure correctly.  I kept turbostat running while performing a
s2idle and recorded the output:

https://gist.githubusercontent.com/tomlanyon/3238e742a155e7fa27658aa0960bdee4/raw/98b5f050e5eb2f88af47b2afd17080e7dd85d20f/turbostat

I'm not familiar with the output format - I see some high percentages
of C10, but nothing in Pkg%pc10. Which is of interest in this
scenario?

On 28 June 2017 at 02:14, Srinivas Pandruvada
<srinivas.pandruvada@...ux.intel.com> wrote:
> Also make sure that you have no FW loading error for i915.
> #dmesg | grep i915
> It will display that Guc FW was loaded etc..
> The latest FW can be downloaded from
> https://01.org/linuxgraphics/downloads/firmware
>
> If you don't see PC10 residency, we can try something more.

I've confirmed that there's no FW errors for the i915.