linux-kernel - Re: [PATCH] intel-vbtn: match power button on press rather than release

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Message-ID: <20170804172953.GC21169@fury>
Date:   Fri, 4 Aug 2017 10:29:53 -0700
From:   Darren Hart <dvhart@...radead.org>
To:     Mario Limonciello <mario.limonciello@...l.com>
Cc:     AceLan Kao <acelan.kao@...onical.com>, linux-pm@...r.kernel.org,
        "Rafael J . Wysocki" <rjw@...ysocki.net>,
        LKML <linux-kernel@...r.kernel.org>,
        platform-driver-x86@...r.kernel.org, Len Brown <lenb@...nel.org>,
        Srinivas Pandruvada <srinivas.pandruvada@...ux.intel.com>
Subject: Re: [PATCH] intel-vbtn: match power button on press rather than
 release

On Fri, Aug 04, 2017 at 12:00:06PM -0500, Mario Limonciello wrote:
> This fixes a problem where the system gets stuck in a loop
> unable to wakeup via power button in s2idle.
> 
> The problem happens because:
>  - press power button:
>    - system emits 0xc0 (power press), event ignored
>    - system emits 0xc1 (power release), event processed,
>      emited as KEY_POWER
>    - set wakeup_mode to true
>    - system goes to s2idle
>  - press power button
>    - system emits 0xc0 (power press), wakeup_mode is true,
>      system wakes
>    - system emits 0xc1 (power release), event processed,
>      emited as KEY_POWER
>    - system goes to s2idle again
> 
> To avoid this situation, process the presses (which matches what
> intel-hid does too).
> 
> Verified on an Dell XPS 9365
> 
> Signed-off-by: Mario Limonciello <mario.limonciello@...l.com>

This looks good to me - responding to the release is non-intuitive IMHO
anyway.  I'd like to see agreement from AceLan, but this should go into
the 4.13 rc cycle (at rc3 currently).

-- 
Darren Hart
VMware Open Source Technology Center