Comment 21 for bug 1506817

A lot has happened since I last checked in. Here is a quick Exec Summary:

I was running kernel 4.5-rc3 and everything was great. Then sometime around Feb 3, 2016 (I dont know the exact date),
following an standard upgrade from Ubuntu, the old symptoms (left mouse button sticking) returned.
While I have some theories about what happened, I'll just stick to the facts (aka, synaptic touch pad (TP) bug).

Long story short, I reinstalled 15.10 from scratch on a new hard drive. I went the path of 14.04 -> 15.10, for reasons I wont go into.

So I ended up with a brand new install of 15.10. This also, like the system I abandoned, had the synaptic TP bug.

Next I installed the latest kernel 4.6 (vmlinuz-4.6.0-040600rc1-generic). This also showed the TP bug.

Finally I installed 4.5-rc3 (vmlinuz-4.5.0-040500rc3-generic). Amazing, it worked, and the TP bug was gone!

Summary:
4.5rc3 started failing on 15.10 around Feb 3, following an upgrade, but once I installed it on a fresh system, it started to work.

More very important additional information:

1) It is now very easy to determine if the system will work (no TP bug) or will not work (TP bug) follwoing the boot, but before
login. If the synaptic touchpad responds (the mouse can be moved via the touch pad) BEFORE login, then the TP bug is present.

2) The presents of the TP bug is perfectly correlated with the post-boot/pre-login test (i.e., the presents of the TPad being on, or off.)

3) The X250 BIOS (latest version) has an option to turn off the TPad, and/or the TP mouse.

4) When I turn off the TPad using the BIOS, the non-working kernels ignore this BIOS option. Let me restate that:
When I turn off the TPad using the BIOS, every kernel that has the Pad bug, ignores the BIOS option. Kernel 4.5rc3, which
does not show the TPad bug, honors the BIOS options.

5) If I turn ON the Tpad with 4.5rc3, the TPad bug is present. Note that this demonstrates that 4.5rc3 listens to the BIOS TP options.

Questions to you:
1) What should I do next, given this new information?
2) Has the problem been isolated to the synaptic modules? Is that how the TPad bug returned with the 4.5rc3 kernel?
Opinion: It seems not to be the kernel, but something else, as I was booting 4.5-rc3 when it started failing, around Feb 2.

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