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From: Tom Lanyon <tom@oneshoeco.com>
Date: Tue, 27 Jun 2017 15:50:33 +1000
Message-ID: <CA+b4Kqd9qV0Pc7wJ2eHKcA-7+a23tY9gfe2Abm4=Bd08SKkh8w@mail.gmail.com>
Subject: Re: [PATCH] ACPI / sleep: EC-based wakeup from suspend-to-idle on
 recent systems
To: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Cc: Linux ACPI <linux-acpi@vger.kernel.org>,
        Linux PM <linux-pm@vger.kernel.org>,
        Andy Shevchenko <andriy.shevchenko@linux.intel.com>,
        Darren Hart <dvhart@infradead.org>,
        LKML <linux-kernel@vger.kernel.org>,
        Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>,
        Mika Westerberg <mika.westerberg@linux.intel.com>,
        Mario Limonciello <mario.limonciello@dell.com>,
        =?UTF-8?B?SsOpcsO0bWUgZGUgQnJldGFnbmU=?= 
        <jerome.debretagne@gmail.com>,
        "Zheng, Lv" <lv.zheng@intel.com>,
        Linus Torvalds <torvalds@linux-foundation.org>
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On 23 June 2017 at 12:40, Linus Torvalds <torvalds@linux-foundation.org> wrote:
> On Thu, Jun 22, 2017 at 4:56 PM, Rafael J. Wysocki <rjw@rjwysocki.net> wrote:
>>
>> Some recent Dell laptops, including the XPS13 model numbers 9360 and
>> 9365, cannot be woken up from suspend-to-idle by pressing the power
>> button which is unexpected and makes that feature less usable on
>> those systems.  [ details removed ]
>
> This looks much more reasonable and more likely to work on future machines too.
>
> Of course, who knows what broken machines it will cause problems on,
> but it sounds like the code now does what it's supposed to and what
> Win10 does, so maybe it JustWorks(tm). Hah.

Rafael - thanks for your efforts on this.

I wanted to provide some feedback from some quick and naive tests on
an XPS 13 9365 in case it was useful, as it seems like there's still
some way to go before matching Win10's behaviour.

    Linux idling w/ screen ON => 17% battery drain per hour.
    Linux idling w/ screen OFF => 12% battery drain per hour.
    Linux during s2idle => 6% battery drain per hour.
    Win10 during sleep => 1% battery drain per hour.

where Linux = 4.12-rc6 + the latest patch from your acpi-pm-test branch.

So whilst s2idle halves the battery drain compared to the machine
staying powered on, it's still significantly more draining than Win10.
Let me know if there's any more useful analysis I can do.

-Tom