Touchpad

Revision 1 as of 2010-07-20 13:08:32

Clear message

Debugging Central

This page is part of the debugging series — pages with debugging details for a variety of Ubuntu packages.

Introduction

Problems with touchpad detection typically fall into one off these categories:

  1. Your touchpad doesn't work at all.
  2. Your touchpad stops working after a while.
  3. Some features of your touchpad like scrolling, tapping, dragging don't work (as expected).

How to file the bug report

Consider this document on filing touchpad bugs with relevant information. Before filing a bug please check the list of known bugs at the end of this document. If your are unsure in which package to file the bug or your problem is not listed in the categories listed here in general file your touchpad related bugs against xserver-xorg-input-synaptics. If the bug turns out to be a kernel bug or a bug in another package, bug triagers should assign the bug additionally to that package or kernel and mark the xserver-xorg-input-mouse task as invalid.

General information before filing the bug

This information should be provided in the bug discription itself.

1. Laptop model. 1. Manufacturer of the Touchpad. 1. When the symptom first appeared.

Sample Description - 'ALPS Touchpad' incorrectly detected as PS/2 mouse in 'Sony Vaio VPCCW16FG' after the kernel upgrade.

However if you think that the bug is a general one with the type of the touchpad and is irrespective of the Laptop model you could emit mentioning the Laptop model in the description. But only consider this if you are very sure and do mention the laptop model in the bug report. This will make the bug more general.

In case your touchpad doesn't work at all (No response from the touchpad)

  1. File the bug against linux

  2. Provide the general information.

  3. Enter the following command in a terminal/console:

    $ dmesg > ~/dmesg 
  4. Attach ~/dmesg and your /var/log/Xorg.0.log to the bug report in separate attachments.

In case your touchpad stops working after a while

  1. Provide the general information.

  2. Direct after logging in to GNOME, KDE or Xfce open a terminal and enter the following commands:

    $ dmesg > ~/dmesg_boot
    $ cp /var/log/Xorg.0.log ~/Xorg.0.log 
  3. Wait until your touchpad stops working.
  4. Open a Virtual Terminal by pressing Ctrl-Alt-F1.
  5. Enter the following commands:

    $ LANG=C
    $ dmesg > ~/dmesg
    $ diff -ns ~/dmesg_boot ~/dmesg > ~/dmesg_diff
    $ cp /var/log/Xorg.0.log ~/Xorg.0.log_tmp
    $ diff -ns ~/Xorg.0.log ~/Xorg.0.log_tmp > ~/Xorg.0.log_diff 
  6. Attach ~/dmesg_boot, ~/dmesg_diff, ~/Xorg.0.log and ~/Xorg.0.log_diff to the bug report in separate attachments.

In case your touchpad is incorrectly detected as a PS/2 mouse (cursor moves but features such as scrolling and tapping does not work)

This happens when 'Touchpad' Tab is not there in System>Preferences>Mouse. In addition you can view your devices file and look there for confirmation : cat /proc/bus/input/devices Here you can see a PS/2 mouse while you have connected it, this is infact your touchpad.

This is in general a wrong detection by the kernel itself. So xserver-xorg-input-synaptics has nothing to do with it. In this case file a bug against the kernel(linux).Also note that you should not mark the bug as duplicate even if you can find a closely related bug and you have a strong feeling that the bug should be duplicate. This is a new policy of Kernel Team and it help them to handle the bugs better.

Include the outputs of the following commands: 1.cat /proc/bus/input/devices >~/devices 2.sudo lspci -vvnn > ~/lspci 3, IMP: Please do not file bug against the kernel unless you are very sure that it should be filed and do it only after reading this whole document. If your are unsure file it against xserver-xorg-input-synaptics, somebody will change to kernel if is so.

== In case touchpad is detected correctly by the kernel but some features such as scrolling, additional buttons, dragging does not work.

In case your all features work but does not work as expected

In case your multitouch features does not work

Before filing new bug please look in the common bugs section.

  1. File bug against xserver-xorg-input-synaptics

  2. Open a terminal and enter the followning commands one by one.
    • cat /proc/bus/input/devices > ~/devices dmesg > ~/dmesg cat /var/log/Xorg.0.log >~/Xorg.0.log

Look your user folder for these files created and upload these files in seperate attachments.


CategoryBugSquad CategoryDebugging