X: touchpad (Synaptics) works only if "CorePointer" with kernel 2.6.26
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X: touchpad (Synaptics) works only if "CorePointer" with kernel 2.6.26
Hello!
I've just compiled the new 2.6.26 kernel. Everything works fine, except the touchpad in X. If I don't start X, the touchpad works fine (with gpm).
If I start X, the touchpad works only if I set it as a "CorePointer" device in xorg.conf; if I write "AlwaysCore", the touchpad doesn't work anymore.
It's strange, because with the old kernel (2.6.24.5, from Slackware installation DVD) the touchpad works both as CorePointer and as AlwaysCore. I need to set it as AlwaysCore because I want my USB mouse to be CorePointer, so that I can set its acceleration factor (the default value is too high; by the way, I didn't find a configuration line in xorg.conf which allows me to set the acceleration and threshold values for a mouse, does anybody know anything about?).
How can the kernel influence X in this way?
Thanks!
This is a tough one. I'm migrating to 2.6.26 myself and have an Alps Glidepoint, which is treated the same as a Synaptics. I rarely use it
(I hate touchpads), but I'll have to investigate it.
One idea I suggest is that, since this seems to be a kernel problem, run a diff against psmouse.c between the kernel versions to see what's changed, if anything. If they're the same, something else is going on.
One other idea is to make sure the same options are being used with these devices between both kernels. In particular, what device is the X
server looking at? My guess is that maybe, if both the touchpad (again, presumably on the PS/2 mouse interface) and your USB mouse are both
in the system, the kernel may be mapping them to different devices. Moving over to the "evdev" interface may solve this, but I worry about the security of that interface and don't like to enable it.
Hopefully this helps a little. Let us know what you find out.
I haven't done my tests to see what the problem is. Anyway, it's not related to the Synaptics. If I set the Synaptics mouse as "CorePointer" and the USB mouse as "AlwaysCore", then the USB mouse doesn't work anymore.
It seems that "AlwaysCore" devices don't work... I think I'll have a look at the kernel sources...
I ran into this on Slackware 12.1 and I was under the impression that it was an X issue, not a kernel issue. From what I've read, the "AlwaysCore" directive was deprecated for pointing devices at least and replaced by the "SendCoreEvents" directive. So in your SeverLayout section, replace AlwaysCore with SendCoreEvents and then for every device you use SendCoreEvents, you'll need to add Option "SendCoreEvents" "true" to the appropriate InputDevice section.
I've got my xorg.conf posted on my help site if that helps clarify things.
Thanks you very much. That worked. I had tried adding the SendCoreEvents option, but I had left the device as "AlwaysCore".
It's strange though that with my old kernel (2.6.24.5) "AlwaysCore" would work.
Anyway, thanks!
Just out of curiosity, do you have both kernels (2.6.26 and 2.6.24.5) installed? Like I said, I thought this was an X problem, but if you can have AlwaysCore work with 2.6.24.5 but not with 2.6.26 and everything else remains the same, that suggests that what I've seen isn't correct.
Summarizing:
- All troubles start if using X; if I don't start X, using gpm both USB mouse and touchpad work.
- The "SendCoreEvents" solution works with both kernels.
- The "AlwaysCore" solution works only with 2.6.24.5 - it seems strange to me too, anyway, since "SendCoreEvents" works, I'll
put this in the "Unexplainable misteries of Linux" category :-)
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