Re: [PATCH] dell-wmi: add module param to control Dell Instant Launch hotkey processing

From: "Pali Rohár" <pali.rohar@gmail.com>
To: "Michał Kępień" <kernel@kempniu.pl>
Cc: Matthew Garrett <mjg59@srcf.ucam.org>,
	Darren Hart <dvhart@infradead.org>,
	platform-driver-x86@vger.kernel.org,
	linux-kernel@vger.kernel.org
Subject: Re: [PATCH] dell-wmi: add module param to control Dell Instant Launch hotkey processing
Date: Thu, 26 Nov 2015 15:41:33 +0100	[thread overview]
Message-ID: <20151126144130.GI14190@pali> (raw)
In-Reply-To: <1f6ac54784b39ebb6ce02a9fb9e944c840fddb7b.1448547341.git.kernel@kempniu.pl>

On Thursday 26 November 2015 15:18:32 Michał Kępień wrote:
> On some laptop models (e.g. Dell Vostro V131), pressing the Dell Instant
> Launch hotkey does not raise an i8042 interrupt - only WMI event 0xe025
> is generated.  As there is no flawless way to determine whether a given
> machine is capable of simulating a keypress when this hotkey is pressed,
> a new module parameter is added so that the user can decide whether the
> WMI event should be processed or ignored.
> 
> Signed-off-by: Michał Kępień <kernel@kempniu.pl>
> ---
> As my last message [1] in the rather lengthy thread failed to elicit any
> response, I guess I might just as well post the proposed patch so that
> we have something specific to discuss.
> 
> [1] http://www.spinics.net/lists/platform-driver-x86/msg07679.html
> 

Can you wait just a little bit? Till end of month two Dell kernel devs
are on vacation, so after that they maybe answer to question about new
hotkey format/support in kernel.

>  drivers/platform/x86/dell-wmi.c |    9 ++++++++-
>  1 file changed, 8 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/platform/x86/dell-wmi.c b/drivers/platform/x86/dell-wmi.c
> index 8cb0f57..e68ce3b 100644
> --- a/drivers/platform/x86/dell-wmi.c
> +++ b/drivers/platform/x86/dell-wmi.c
> @@ -44,6 +44,10 @@ MODULE_LICENSE("GPL");
>  #define DELL_EVENT_GUID "9DBB5994-A997-11DA-B012-B622A1EF5492"
>  
>  static int acpi_video;
> +static bool process_dil;
> +
> +module_param(process_dil, bool, 0644);
> +MODULE_PARM_DESC(process_dil, "Generate an input event when the WMI event for Dell Instant Launch hotkey is received");

I do not like name "dil". It takes me few minutes to interpret it as
Dell Instant Launch...

Also I do not know if this is the best approach.

>  	/* Shortcut and audio panel keys */
> -	{ KE_IGNORE, 0xe025, { KEY_RESERVED } },
> +	{ KE_KEY, 0xe025, { KEY_PROG4 } },
>  	{ KE_IGNORE, 0xe026, { KEY_RESERVED } },

I'm trying to figure out if those two keys are really reported via
keyboard controller or not. They were added 4 years ago in commit
f1566f0dc07ec9b5409b348070f5a700032d7881. But from bug report
http://bugs.launchpad.net/bugs/815914 there is no information if those
two keys are really reported by keyboard controller or not.

And if not our problem could be easier...

-- 
Pali Rohár
pali.rohar@gmail.com