Thursday, November 18, 2010

How to ignore configuration errors

Two common errors turning up in the log files are "(EE) ioctl EVIOCGNAME failed: Inappropriate ioctl for device" and "(--) SynPS/2 Synaptics TouchPad: no supported touchpad found".

One example for the former is:

[ 59.837] (II) config/udev: Adding input device ADS7846 Touchscreen (/dev/input/event3)
[ 59.837] (**) ADS7846 Touchscreen: Applying InputClass "default"
[ 59.841] (**) ADS7846 Touchscreen: Applying InputClass "evdev touchscreen "
[ 59.842] (**) ADS7846 Touchscreen: always reports core events
[ 59.842] (**) ADS7846 Touchscreen: Device: "/dev/input/event3"
[ 59.842] (--) ADS7846 Touchscreen: Found absolute axes
[ 59.842] (--) ADS7846 Touchscreen: Found x and y absolute axes
[ 59.842] (--) ADS7846 Touchscreen: Found absolute touchscreen
[ 59.843] (II) ADS7846 Touchscreen: Configuring as touchscreen
[ 59.843] (**) ADS7846 Touchscreen: YAxisMapping: buttons 4 and 5
[ 59.843] (**) ADS7846 Touchscreen: EmulateWheelButton: 4, EmulateWheelIner0
[ 59.845] (II) XINPUT: Adding extended input device "ADS7846 Touchscreen" ()
[ 59.851] (II) ADS7846 Touchscreen: initialized for absolute axes.

--------------------- divider added for clarity ----------------

[ 59.854] (II) config/udev: Adding input device ADS7846 Touchscreen (/dev/input/mouse0)
[ 59.854] (**) ADS7846 Touchscreen: Applying InputClass "default"
[ 59.855] (**) ADS7846 Touchscreen: always reports core events
[ 59.855] (**) ADS7846 Touchscreen: Device: "/dev/input/mouse0"
[ 59.855] (EE) ioctl EVIOCGNAME failed: Inappropriate ioctl for device
[ 59.856] (II) UnloadModule: "evdev"
[ 59.856] (EE) PreInit returned NULL for "ADS7846 Touchscreen"


One example for the latter:


[   494.925] (II) config/udev: Adding input device SynPS/2 Synaptics TouchPad (/dev/input/event6)
[   494.925] (**) SynPS/2 Synaptics TouchPad: Applying InputClass "evdev touchpad catchall"
[   494.925] (**) SynPS/2 Synaptics TouchPad: Applying InputClass "touchpad catchall"
[   494.925] (II) LoadModule: "synaptics"
[   494.927] (II) Loading /usr/lib/xorg/modules/input/synaptics_drv.so
[   494.927] (II) Module synaptics: vendor="X.Org Foundation"
[   494.927]  compiled for 1.9.0, module version = 1.3.99
[   494.928]  Module class: X.Org XInput Driver
[   494.928]  ABI class: X.Org XInput driver, version 11.0
[   494.928] (II) Synaptics touchpad driver version 1.3.99
[   494.928] (**) Option "Device" "/dev/input/event6"
[   495.282] (--) SynPS/2 Synaptics TouchPad: x-axis range 1472 - 5682
[   495.282] (--) SynPS/2 Synaptics TouchPad: y-axis range 1408 - 5076
[   495.282] (--) SynPS/2 Synaptics TouchPad: pressure range 0 - 255
[   495.282] (--) SynPS/2 Synaptics TouchPad: finger width range 0 - 0
[   495.283] (--) SynPS/2 Synaptics TouchPad: buttons: left right
[   495.283] (--) SynPS/2 Synaptics TouchPad: invalid finger width range.  defaulting to 0 - 16
[   495.522] (--) SynPS/2 Synaptics TouchPad: touchpad found
[   495.522] (**) SynPS/2 Synaptics TouchPad: always reports core events
[   495.682] (II) XINPUT: Adding extended input device "SynPS/2 Synaptics TouchPad" (type: TOUCHPAD)
[   495.683] (**) SynPS/2 Synaptics TouchPad: (accel) MinSpeed is now constant deceleration 2.5
[   495.683] (**) SynPS/2 Synaptics TouchPad: MaxSpeed is now 1.75
[   495.683] (**) SynPS/2 Synaptics TouchPad: AccelFactor is now 0.036
[   495.683] (**) SynPS/2 Synaptics TouchPad: (accel) keeping acceleration scheme 1
[   495.683] (**) SynPS/2 Synaptics TouchPad: (accel) acceleration profile 1
[   495.683] (**) SynPS/2 Synaptics TouchPad: (accel) acceleration factor: 2.000
[   495.683] (**) SynPS/2 Synaptics TouchPad: (accel) acceleration threshold: 4
[   495.842] (--) SynPS/2 Synaptics TouchPad: touchpad found

--------------------- divider added for clarity ----------------

[   495.843] (II) config/udev: Adding input device SynPS/2 Synaptics TouchPad (/dev/input/mouse0)
[   495.843] (**) SynPS/2 Synaptics TouchPad: Applying InputClass "touchpad catchall"
[   495.844] (II) Synaptics touchpad driver version 1.3.99
[   495.844] (**) Option "Device" "/dev/input/mouse0"
[   495.922] (--) SynPS/2 Synaptics TouchPad: invalid x-axis range.  defaulting to 1615 - 5685
[   495.922] (--) SynPS/2 Synaptics TouchPad: invalid y-axis range.  defaulting to 1729 - 4171
[   495.922] (--) SynPS/2 Synaptics TouchPad: invalid pressure range.  defaulting to 0 - 256
[   495.922] (--) SynPS/2 Synaptics TouchPad: invalid finger width range.  defaulting to 0 - 16
[   495.943] (EE) Query no Synaptics: 6003C8
[   495.943] (--) SynPS/2 Synaptics TouchPad: no supported touchpad found
[   495.943] (EE) SynPS/2 Synaptics TouchPad Unable to query/initialize Synaptics hardware.
[   495.944] (EE) PreInit returned NULL for "SynPS/2 Synaptics TouchPad"


In both cases, you'll notice that the device gets added twice. Once with a /dev/input/eventX device path, and once with a /dev/input/mouseX path. The first one succeeds and that results in your device being added to the X server's device list. The second one fails because both evdev and synaptics try to use an ioctl that is only available on event devices. The errors do not indicate a driver bug but a misconfiguration. The local configuration needs to be adjusted to avoid non-event devices being assigned to evdev or synaptics.

Look at the synaptics xorg.conf.d snippet we ship in Fedora:

Section "InputClass"
        Identifier "touchpad catchall"
        Driver "synaptics"
        MatchIsTouchpad "on"
        MatchDevicePath "/dev/input/event*"
EndSection


That last line is important. It only tries to assign the synaptics driver to event devices, not to mouse devices. Once you've added that line (or poked your distro maintainer to do it for you), the errors will go away. Alternatively, you could just ignore the errors and not file a bug for it :)

Note that the synaptics upstream snippet does not contain this line. Synaptics supports more than just Linux so we cannot add this upstream.
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6 comments:

  1. tegNovember 18, 2010 at 2:18 PM

    I ran across this misconfiguration error a few weeks back. I just thought I'd add that there is a good reason to fix this beyond getting rid of the error message:
    It reduces the startup of X from almost 4 to a bit more than one second.

    Is possible to fix this upstream inside an #ifdef LINUX? Or some other way so distro's don't have to keep patching it?

    ReplyDelete
  2. Peter HuttererNovember 18, 2010 at 2:23 PM

    uhm, I'm not sure where to place that ifdef. The only correct integration for this is to add it to the driver to strcmp for /dev/input/mouse, but by then you're already in the initialization process and the device would still fail to initialize with some error message.

    The server _could_ do driver + device path matching, but just because we can do it doesn't mean it's a good idea :)

    ReplyDelete
  3. tegNovember 18, 2010 at 2:30 PM

    I meant to suggest that the snippet (50-synaptics.conf) could be generated by make so it would be different on Linux and non-Linux systems.

    ReplyDelete
  4. Peter HuttererNovember 18, 2010 at 2:43 PM

    that would only solve the synaptics case, not the other one described here.

    also, distributions are likely to have their local hacks anyway, in Fedora we have a couple of blacklists and special device hacks in the various .conf files. Ubuntu and Debian have the same, AFAIK.

    So distros already patch this file anyway, one more line doesn't hurt.

    ReplyDelete
  5. Dan NicholsonNovember 18, 2010 at 4:46 PM

    Shooting from the hip a bit, but you could add a class to ignore these devices in general.

    Section "InputClass"
    Identifier "Ignore mouse devs"
    MatchDevicePath "/dev/input/mouse*"
    Option "Ignore" "true"
    EndSection

    I can't think of any times when we want the mouse devices on Linux.

    ReplyDelete
  6. UnknownDecember 28, 2014 at 8:26 PM

    My touchpad was not working on Arch Linux, but this helped and it's now fixed, thanks! ;)

    ReplyDelete

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