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

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Date:   Thu, 06 Jul 2017 17:38:53 -0700
From:   Srinivas Pandruvada <srinivas.pandruvada@...ux.intel.com>
To:     Tom Lanyon <tom@...shoeco.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

On Thu, 2017-07-06 at 21:41 +1000, Tom Lanyon wrote:
> 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/3238e742a155e7fa27658aa0
> 960bdee4/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?
I see that you do have Pkg%pc10 of 86.56 in one interval. The system
was in Pkg%pc8 for multiple intervals before Pkg%pc10. So can you try
this also before your test?

# cd /sys/kernel/debug/pmc_core
# for i in {0..32}; do echo $i > ltr_ignore; done

Thanks,
Srinivas	

> 
> 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.