Re: [PATCH v2] dell-wmi: process Dell Instant Launch hotkey on Dell Vostro V131

From: "Pali Rohár" <pali.rohar@gmail.com>
To: "Michał Kępień" <kernel@kempniu.pl>
Cc: Matthew Garrett <mjg59@srcf.ucam.org>,
	platform-driver-x86@vger.kernel.org,
	linux-kernel@vger.kernel.org, Andy Lutomirski <luto@kernel.org>,
	Darren Hart <dvhart@infradead.org>
Subject: Re: [PATCH v2] dell-wmi: process Dell Instant Launch hotkey on Dell Vostro V131
Date: Thu, 21 Jan 2016 16:42:48 +0100	[thread overview]
Message-ID: <20160121154248.GI7192@pali> (raw)
In-Reply-To: <20160121145612.GA4684@eudyptula.hq.kempniu.pl>

On Thursday 21 January 2016 15:56:12 Michał Kępień wrote:
> > > > Michał, can you prepare new (v3) version of this patch? Now required
> > > > acpi video changes are included and so dell-wmi changes should go to...
> > > > To finally fix this keypress bug on Dell Vostro V131 machine.
> > > 
> > > I keep this on my to-do list, but the updated patch will depend on the
> > > final version of the SMBIOS API rework, so I guess there is little point
> > > in posting it now as that API is subject to change.  But rest assured
> > > that as soon as the final version of the API rework series (which I have
> > > yet to prepare, of course) gets applied by Darren, I will post a v3 of
> > > this patch - after all, it is the very reason I am working on the API
> > > rework.
> > 
> > There is still need to patch dell-wmi.c? And this change does not depend
> > on another SMBIOS change (in dell-laptop), right?
> 
> Well, back in December, you wrote [1]:
> 
> > This patch is not enough for enabling 0xe025 key on that Vostro machine.
> > Some extra SMBIOS call is needed, without them ACPI will not send WMI
> > keypress event.
> > 
> > (...)
> > 
> > Maybe now it could make sense to unify Dell SMBIOS API in kernel and
> > move common functions to one place and let drivers to use just common
> > functions. According to older Dell ACPI WMI documentation in DMI is bit
> > which specify if BIOS support SMBIOS via WMI or not.
> > 
> > At least I think this one patch should not be included into kernel until
> > there will be full support for 0xe025 key (adding that SMBIOS call).
> 
> From the above I understood that first you want to unify the Dell SMBIOS
> API used throughout the kernel (that's currently in progress), so that
> it can then be used in dell-wmi as well to perform the SMBIOS call
> needed on the Vostro V131.
> 
> If you want me to just rework the patch so that it doesn't introduce a
> quirk structure, I recalled another reason to use it after all: there
> are other Dell laptops which require the special SMI for enabling WMI
> events, but report the Dell Instant Launch Hotkey using a different WMI
> event code [2].  So I'd say that two separate issues should be fixed
> using DMI matching:
> 
>   * whether the special SMBIOS call is required,
>   * whether the 0x0e25 event should be translated into a keypress.
> 
> A quirk structure looks like an elegant way to deal with this.
> 
> Could you please advise how you would like me to proceed with this?
> 
> [1] http://www.spinics.net/lists/platform-driver-x86/msg07845.html
> [2] https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1205791/comments/12
> 

Hm...

For full support we need:

1) invoke special SMBIOS call for some machine

2) patch dell-wmi.c to do not drop some events for some machines

Part 2) needs to touch only dell-wmi.c code, this is obvious. But I
thought that part 1) will be done in dell-laptop.c code where are all
others SMBIOS calls. Reason is just because dell-wmi.c is doing WMI
stuff. Do you want to include this is part 1) also to dell-wmi.c file?

-- 
Pali Rohár
pali.rohar@gmail.com