input event/mouse detection from evdev/x server

Daniel Stone daniel at
Fri Jan 28 12:46:16 PST 2011


On Fri, Jan 28, 2011 at 04:56:45PM +0000, Popescu, CatalinX wrote:
> I have an issue with the X server, evdev library more precisely. When a mouse (or a compatible device) is detected by the X server, the server does actually detect an event device (/dev/input/eventN) and a mouse device (/dev/input/mouseN). On the event device detection is successful, but the mouse detection fails because of the EVIOCGNAME ioctl failing. As a result the evdev module gets unloaded. Depending on which detection happens in first place the mouse will/won't work :

EVIOCGNAME failing is a good sign that it's not actually an evdev

> [    18.691] (**) Logitech USB-PS/2 Optical Mouse: always reports core events
> [    18.691] (**) Logitech USB-PS/2 Optical Mouse: Device: "/dev/input/mouse0"
> [    18.695] (EE) ioctl EVIOCGNAME failed: Inappropriate ioctl for device
> [    18.707] (II) UnloadModule: "evdev"
> Can someone explain why there are 2 input "devices" detected by X server for one physical mouse? How can this be fixed? Is it an issue with the evdev kernel driver or an issue with X server/evdev extension?

Indeed, /dev/input/mouse* aren't evdev devices, they're legacy
PS/2-alike mouse devices.  You don't need to use or worry about them:
/dev/input/event* should work.

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