Friday, November 20, 2015

Synaptics touchpad erratic on Knoppix 7.x

The title is self-explanatory. I first discovered this issue with Knoppix 7.0.5 (IIRC), and it continued "well" into Knoppix 7.2 CD versions. I prefer to use CD versions of Knoppix, because of a lack of storage and download speeds. Yes! Mmh!!

Note that to avoid fancy Compiz effects, I almost always use the no3d parameter at Knoppix startup.

The Synaptics touchpad is highly erratic (in Metacity), and until today I had had no solution to make it less erratic. One of the symptoms in a browser, for example, is that text suddenly gets selected and I can't release the selection. No, nothing helps. I could only use the keyboard to navigate, and LXDE/Metacity environments don't appear to have any keyboard shortcut to access the taskbar (start) menu.

There are two things to to keep in mind:
  1. One of the possible solutions is to fall back to Knoppix 6.7.1, which allows a stable pointer with the Synaptics touchpad, but this Knoppix release has outdated software (Iceweasel 6.0, for example).
  2. A workaround in Knoppix 7.x consists of adding the psmouse parameter into the Knoppix start-up command-line:
    knoppix no3d psmouse.proto=imps
    The imps somehow changes the pointer input device. At least on my machine, the immediate effect was that cursor tracking with the touchpad became slower.

    While the terrible and annoying erratic behaviour was not there as much, it still kept being somewhat erratic in other ways, albeit less and in a more manageable manner. Then I discovered the following:
  3. The thing is to never open the CompizConfig Settings Manager. — Because I noticed that it will start changing settings right after it's started or when a user changes settings on their own. That way I have been able to evade issues that cause the pointer misbehave so terribly.

No comments: