Adding xorg-x11-drv-libinput to the Desktop's set of default packages

[Christian Schaller]

----- Original Message -----
> From: "Hans de Goede" <hdegoede at redhat.com>
> To: desktop at lists.fedoraproject.org
> Sent: Tuesday, January 13, 2015 4:21:52 AM
> Subject: Re: Adding xorg-x11-drv-libinput to the Desktop's set of default	packages
> 
> Hi,
> 
> On 13-01-15 00:48, Peter Hutterer wrote:
> > On Mon, Jan 12, 2015 at 04:12:01PM +0100, Hans de Goede wrote:
> > [...]
> >>>> Running KDE apps on top of the GNOME desktop will not be affected,
> >>>> actually even with xorg-x11-drv-libinput installed KDE itself will
> >>>> still work fine, the only thing which will not work is KDE's
> >>>> configuration
> >>>> applet for configuring touchpad settings like tap-to-click.
> >>>>
> >>>> If KDE users have xorg-x11-drv-libinput installed (somehow) and they
> >>>> want something else then the default touchpad behaviour they can still
> >>>> get it but the will need to use xinput from the commandline to change
> >>>> the settings; or they can simply do "rpm -e xorg-x11-drv-libinput",
> >>>> restart X and have everything as it was in F-21, even if they started
> >>>> with the desktop product.
> >>>>
> >>>> We are planning a gradual transition here, where both the old and new
> >>>> xorg drivers will be supported, independent of the DE really, but we
> >>>> would like to slowly move towards the new driver, so for F-22 the plan
> >>>> is to have GNOME's input configuration bits know how to talk to either
> >>>> driver, and have the new driver installed by default on the desktop
> >>>> product.
> >>>
> >>> Can't we just make whatever the package that contains the KDE control
> >>> panel to carry a /etc/X11/xorg.conf.d/ snippet that enables the
> >>> synaptics driver?
> >>> That way you get libinput by default and synaptics if you install KDE
> >>> ... as GNOME handles both it won't break GNOME.
> >>>
> >>> In F23 once KDE is ported we can stop shipping that file.
> >>
> >> Hmm, interesting suggestion, I've been unable to find clear documentation
> >> on the ordering of parsing xorg.conf.d snippets in general, and the
> >> ordering of parsing stuff under /usr/share/X11 vs under /etc .
> >>
> >> Peter, can you shed some light on the parsing ordering (we should really
> >> add something about this to "man xorg.conf".
> >>
> >> Peter, what do you think about Draco's suggestion ?
> >
> > The lookup order is (in lowest priority first):
> > /usr/share/X11/xorg.conf.d
> > /etc/X11/xorg.conf.d/
> > /etc/X11/xorg.conf
> >
> > with the directories being read in sorted order (but /etc always overrides
> > /usr). we only ship snippets in /usr/share and leave /etc up to the user,
> > so
> > that's what KDE would have to do as well.
> >
> > There are two drawbacks to this approach:
> > First, we can't remove synaptics/evdev because many people have a
> > copy-pasted InputClass snippet that includes the Driver "synaptics" or
> > "evdev" line.  That'll override any system config so if we don't have the
> > drivers installed those users get dead devices. Fixable in the server by
> > setting libinput if the module isn't present but that needs to be done
> > upstream first.
> >
> > Second, config files can only add up and override, not remove options. But
> > we can match on already-assigned driver, so this should work:
> > Section "InputClass"
> >     Identifier "restore synaptics"
> >     MatchDriver "libinput"
> >     MatchIsTouchpad "on"
> >     Driver "synaptics"
> > EndSection
> 
> Ah yes, that should work, and kcm_touchpad could install that with a high
> priority. That might be a good solution, I say might because I'm not 100%
> sold
> on this, this means that a user installing KDE once, just to give it a try,
> will then be moved back to synaptics and things will stay that way.

This does not sound good to me and it sounds like it would be in breach of one
of the defined principles of the Fedora Workstation:
"The Workstation working group will define a set of packages that are considered required be installed in order for the system to qualify as a Fedora Workstation. 
Through policy users will be strongly advised against uninstalling any of these packages and there will also be no option in the graphical software installer to 
uninstall them. Any optional packages for the Fedora Workstation can not obsolete or in any other way try to remove or disable these packages."

This seems to fall foul with the last sentence since it disables one of the standard packages of the Workstation.


> It may be better to just tell people to do "rpm -e xorg-x11-drv-libinput" if
> they started with the Workstation product and want to use kcm_touchpad, AFAIK
> kcm_touchpad will register itself with the KDE control-panel if the synaptics
> driver is loaded, so if we end up using libinput kcm_touchpad will simple not
> show, rather then break.
> 
> So opinions on this anyone ?

I prefer this one, as per the policy mentioned above this way at least people make
an active choice to 'mess up' their system as opposed to packages being installed
doing it 'silently'.

Christian