Last round of xorg updates broke mouse acceleration for my ALPS touchpad

[Clemens Eisserer]

Hi,

The last round of F20 updates broke mouse acceleration for the ALPS
touchpad integrated into my dell latitude E6320.
Moving the mouse pointer with the touchpad is super-slow, and changing
the acceleration slider in xfce's mouse settings doesn''t change a
thing.
External USB mice work fine.

How should I proceed with a bug report? I know there is some kind of
voting system to flag new packages as problematic, but I don't even
know which package causes the issue or how I could switch to an
earlier revision (does yum allow to "rollback" an update?).

Thank you in advance, Clemens