Re: [PATCH] ACPI video: Add video_switch_key option

[Takashi Iwai <tiwai@suse.de>]

At Wed, 24 Nov 2010 14:26:18 +0000,
Matthew Garrett wrote:
> 
> On Wed, Nov 24, 2010 at 08:05:35AM +0100, Takashi Iwai wrote:
> > Hi,
> > 
> > At Wed, 27 Oct 2010 12:39:17 +0200,
> > Takashi Iwai wrote:
> > > Some HP laptops send ACPI video events per lid open/close, and the
> > > ACPI video driver translates to SWITCHVIDEOMODE input key events.
> > > This behavior confuses the user-space daemon such as
> > > gnome-settings-daemon since it changes the video mode per this key,
> > > which results in a different video mode at each time you open/close
> > > the laptop lid.  Fn-Fx keys are handled differently on such hardware,
> > > thus this key generation is simply superfluous.
> > > 
> > > This patch adds a module parameter "video_switch_key" to either
> > > assign a different key code for this ACPI event or disable by setting
> > > zero there.
> > > 
> > > Signed-off-by: Takashi Iwai <tiwai@suse.de>
> > 
> > Any comments on this patch?
> 
> I'm not entirely clear on why this is wanted. Lid state changes seem to 
> be a reasonable proxy for "Reprobe outputs" - what's userspace actually 
> doing that causes problems?

Typically GNOME changes to the next monitor mode (e.g. xinearama,
clone, laptop-only, external-only) by each XF86VideoSwitch key event.
If you connect your laptop to a monitor, and sets to clone mode,
close the lid, and reopen.  Then you'll find the video mode is now
external-monitor only.  It's because two XF86VideoSwitch key events
are issued during close/open the lid.


thanks,

Takashi