Re: [RFC/PATCH] input_id: add touchpad quirks rules file.

[Peter Hutterer <peter.hutterer@who-t.net>]

On Thu, May 13, 2010 at 03:19:59PM +0200, Martin Pitt wrote:
> Peter Hutterer [2010-05-13 14:03 +1000]:
> > I kind-of expect some more tags like this to appear in the future, so I
> > figured the generic name touchpad-quirks is better than have a dell-specific
> > one. Would something like this be appreciated in the upstream repo?
> 
> There's one more dimension to that, where those rules should be
> maintained: We can ship them in udev proper (as your patch proposes),
> or ship the udev rules in the package which will actually make use of
> it, like xorg-input-synaptics (which is what Debian/Ubuntu are
> currently doing).
> 
> My preference is that we should keep subsystem specific rules in the
> subsystem daemon/libraries (like udisks/upower/X.org/libgphoto2)
> instead of centrally managing them in udev, for three reasons:
> 
>  (1) The subsystem daemon maintainers are usually the experts, and know
>      better how that particular hardware should be configured.
>  
>  (2) I hear that udevd will eventually go away, and its probers will
>      be fanned out to the subsystem daemons, therefore leaving the
>      udev package as a relatively stable library only.
>  
>  (3) udev rules and xorg.conf.d/ snippets would be maintained at the
>      same place and can be updated in lockstep, instead of creating a
>      tight dependency relation.
> 
> (3) particularly addresses your remark about the current distro
> inconsistency between tag names.
> 
> If you do not want to maintain those rules in the synaptics package
> for some reason, I would not object to committing them into udev, but
> I think we are a lot less flexible that way.

righty-o, I don't really have a problem with that, getting it into udev was
mostly to stop the duplication efforts. It'd be great though if we had a way
to sync up our rules files and that can simply be in the upstream synaptics
sources.

maintainerwise - anything in synaptics and not in udev is much easier to
maintain for me anyway ;)

> > Looking at the Ubuntu sources for the synaptics driver, the choice there is
> > to simply tag with the model name (e.g. "inspiron_1011") and then have the
> > xorg.conf hook onto this.
> 
> This was by and large arbitrary, since it wasn't clear whether
> different models would need different AreaBottomEdge values.
> 
> For the record, we also have two more quirks [1], which seem quite model
> specific.

yeah, I've seen that part but I think the jumpy cursor threshold could be
worked around in the driver so that that option isn't needed. I just need to
get the mini repaired and running to verify this, some preliminary patches I
had were promising.

fwiw, I'm also working on percentage option support for the X server, so
instead of having hardcoded model-specific values (e.g. 4000 as bottom edge)
you can just specify 20% off the bottom of the touchpad. That again makes
autoconfiguration more generic.

Cheers,
  Peter