linux-kernel - Re: BUG? Duplicate key code 0xe045 in dell-wmi.c

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Message-ID: <20150904103402.GG32350@pali>
Date:	Fri, 4 Sep 2015 12:34:02 +0200
From:	Pali Rohár <pali.rohar@...il.com>
To:	Mario Limonciello <mario_limonciello@...l.com>
Cc:	Matthew Garrett <mjg@...hat.com>,
	Andrew Morton <akpm@...ux-foundation.org>,
	Len Brown <len.brown@...el.com>,
	"platform-driver-x86@...r.kernel.org" 
	<platform-driver-x86@...r.kernel.org>,
	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
	Gabriele Mazzotta <gabriele.mzt@...il.com>,
	Michał Kępień <kernel@...pniu.pl>
Subject: Re: BUG? Duplicate key code 0xe045 in dell-wmi.c

On Tuesday 07 July 2015 23:18:48 Pali Rohár wrote:
> On Tuesday 07 July 2015 13:38:41 Mario Limonciello wrote:
> > 
> > 
> > On 07/04/2015 11:34 AM, Pali Rohár wrote:
> > > Hello,
> > >
> > > I'm looking at dell-wmi.c driver and its history in git and I found 
> > > problem with handling WMI key code 0xe045. In current dell-wmi.c code is
> > >
> > > {KE_KEY, 0xe045, KEY_PROG1},
> > > {KE_IGNORE, 0xe045, KEY_NUMLOCK},
> > >
> > > I bet this is some copy-paste error as one code can be translated only 
> > > to one input key event.
> > >
> > > In git history I found that above change was added by commit:
> > >
> > > http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=5cab0098171712a9fd51399b06181c8dfdebe9c9
> > >
> > > ===============================================
> > > commit 5cab0098171712a9fd51399b06181c8dfdebe9c9
> > > Author: Mario Limonciello <mario_limonciello@...l.com>
> > > Date:   Wed Jun 10 19:40:47 2009 +0000
> > >
> > >     dell-wmi: add additional keyboard events
> > >     
> > >     Upcoming Dell hardware will send more keyboard events via WMI.  Add
> > >     support for them.
> > >     
> > >     Signed-off-by: Mario Limonciello <mario_limonciello@...l.com>
> > >     Signed-off-by: Matthew Garrett <mjg@...hat.com>
> > >     Signed-off-by: Andrew Morton <akpm@...ux-foundation.org>
> > >     Signed-off-by: Len Brown <len.brown@...el.com>
> > > ===============================================
> > >
> > > Sending email to all signers of this commit. Problematic code is still 
> > > in upstream kernel, so it needs to be fixed.
> > >
> > > Mario Limonciello: Do you know if code 0xe045 is some PROG1 or NUMLOCK?
> > >
> > Hi Pali,
> > 
> > Yes this looks like a mistake and that the KEY_PROG1 item should have
> > been removed in that patch.  It should be a notification (KEY_IGNORE)
> > for numlock.
> > 
> > Thanks,
> 
> Hi, I looked into git history of dell-wmi more deeply... into first
> commit of dell-wmi.c source code. It is this one from year 2009:
> 
> https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=0b3f6109f0c9ff926b5ffc80dc1cebb24f192b35
> 
> Here Matthew Garrett says:
> 
> ... send a generic input event when a button with a picture of a battery
> on it is pressed ...
> 
> and adds code:
> 
> +static struct key_entry dell_wmi_keymap[] = {
> +	{KE_KEY, 0xe045, KEY_PROG1},
> +	{KE_END, 0}
> +};
> 
> So basically when "picture of a battery" is pressed WMI send event
> 0xe045 which is translated to KEY_PROG1.
> 
> Matthew Garrett is original author of that code and I believe that on
> some his machine 0xe045 code from DELL WMI really could be sent when
> battery button is pressed.
> 
> Mario, if you as Dell authority says that 0xe045 is sent when numlock is
> pressed, it means either code 0xe045 is ambiguous :-( and has different
> meaning for different machines or there is error in (your) documentation
> or bios... or Matthew cannot differ between picture of battery and
> picture of numlock on his dell machine :-)
> 
> Matthew: If you still reading this email thread, do you know for which
> Dell machine did you write this dell-wmi.c driver originally?
> 
> Mario: Do you know more about this problem?
> 
> 
> From function sparse_keymap_setup() called by dell-wmi.c this structure:
> 
>   {KE_KEY, 0xe045, KEY_PROG1},
>   {KE_IGNORE, 0xe045, KEY_NUMLOCK},
> 
> is decoded that 0xe045 event is *not* ignored and reports KEY_PROG1 key.
> 

Hi Mario! Can you comment something about that KEY_PROG1?

-- 
Pali Rohár
pali.rohar@...il.com
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