recovering from ubuntu 12.04 upgrade issues

Following upgrade to Ubuntu 12.04 LTS, my Dell Latitude E6400 had issues with hardware recognition, namely trackpad and USB mouse input.  This is a pretty vanilla laptop, that I don't mind re-installing.  Being too lazy to troubleshoot deeply my response was to try and fix any broken package dependencies:

 $ sudo apt-get -f install

That resulted in a leading error message pointing to broken dpkg configuration, and that was easily fixed by running:

$ sudo dpkg --configure -a

Then, re-ran the apt-get -f install  (-f is --fix-broken).   That ran successfully to completion, so cleaned up any cruft from the install/fix:

$ sudo apt-get autoremove

Then, rebooted, and all was rainbows and unicorn farts.   Mouse and trackpad input restored.