Bug#469198: Xorg.conf file in "/etc/X11/" incorrectly recognises "Alps-Glidepoint" as "Synaptic Touchpad"

["Venigalla Sayikiran" <vsayikiran@gmail.com>]

Hi Julien
                   You say that there is no "alps driver" as such. According to you there is only synaptic driver which takes care of both synaptics touchpad and Alps glidepoint devices. Below I have given a detail report of my experimentation:

1) I modified the xorg.conf file as follows:
Section "InputDevice"
         Identifier    "Synaptics Touchpad"
         Driver        "synaptics"
         Option        "SendCoreEvents"    "true"
         Option        "Device"        "/dev/psaux"
         Option        "Protocol"        "auto-dev"
         Option     "HorizScrollDelta"    "20"
    Option        "MaxTapTime"     "180"
    Option        "FastTaps"         "1"
    Option        "MaxDoubleTapTime" "100"
    Option    "TouchpadOff"    "0"
    Option    "MaxTapMove"        "110"
    Option    "MaxSpeed"        "1.00"
    Option    "MinSpeed"        "0.50"
EndSection
Section "ServerLayout"
    Identifier    "Default Layout"
    Screen        "Default Screen"
    InputDevice    "Generic Keyboard"
    InputDevice    "Configured Mouse"
    InputDevice    "Synaptics Touchpad"
EndSection

After restarting the laptop i am able to use touchpad but tapping doesn't work. But one of my friends laptop which is also dell, supports tapping feature with these settings. Since he is using synaptics touchpad.

2)Then i changed some fields keeping rest of the options same. I have only given the changed fields below:
Section "InputDevice"
         Identifier    "Synaptics Touchpad"
         Driver        "alps"
----- same as above ---------
----- same as above ---------
End Section
Section "ServerLayout"
------- same as above ------
End Section
Now i restarted my laptop and i saw that tapping is enabled. If at all there is no "alps" driver, then why after the above mentioned change tapping is working.

3) Now i changed the "InputDevice" field in Section "ServerLayout" as follows. So this is my final xorg.conf file.
Section "InputDevice"
         Identifier    "Synaptics Touchpad"
         Driver        "alps"
         Option        "SendCoreEvents"    "true"
         Option        "Device"        "/dev/psaux"
         Option        "Protocol"        "auto-dev"
         Option     "HorizScrollDelta"    "20"
    Option        "MaxTapTime"     "180"
    Option        "FastTaps"         "1"
    Option        "MaxDoubleTapTime" "100"
    Option    "TouchpadOff"    "0"
    Option    "MaxTapMove"        "110"
    Option    "MaxSpeed"        "1.00"
    Option    "MinSpeed"        "0.50"
EndSection
Section "ServerLayout"
    Identifier    "Default Layout"
    Screen        "Default Screen"
    InputDevice    "Generic Keyboard"
    InputDevice    "Configured Mouse"
    InputDevice    "Alps Glidepoint"
EndSection

After restarting my laptop i was unable to load gdm. It gave me an error message.
Error message: "Failed to start the X Server (your graphical interface). It is likely that it is not set up correctly. Would  you like to view the X Server output to diagnose the problem."
At this point i was able to use keyboard only. Then i selected "yes" option.
I saw this message.

X window System Ver. 7.1.1
Release Date: 12 may 2006
X protcol version 11, Revision #0, Release 7.1.1
Build OS: unknown
Current OS: linux ver. 2.6.18-6-686 #1 SMP sun feb 10 22:11:31 UTC 2008 i686
Build date: 24 jan 2008
Module loader present
Markers: (--) probed, (**) from config file, (==) default setting, (++) from command line, (!!) notice, (II) informational, (EE) error, (NI) not implemented, (??) unknown
(==) log file : /var/log/xorg.0.log, time: tue mar 4 22:14:14 2008
(==) using config file: /etc/x11/xorg.conf
undefined input device "alps glidepoint" referenced by server layout "default layout"

  (EE) problem parsing the config file
  (EE) error parsing the config file

Fatal server error. no screen found.

Then i closed above message and i was forced to select "no" option in the first error message i got. After that i was able to login into terminal mode only. Now i am confused by above error message. Why the touchpad settings is affecting gdm?. Finally i changed the xorg.conf to the setting that i have given in step 2. Now i am able to login and use GUI also tapping is working.

You told tapping is disabled by default in your dell laptop. If you are using alps touchpad you can enable it and see if its working or not.

Suggestion: I think there is problem with how xserver-xorg recognises alps and synaptics touchpad. I also think there is a driver called "alps".

Regards
vsayikiran@gmail.com