# Mouse Problems

## DopplerEffect

I've recently gotten my gentoo installation up an running again, using KDE 4.2 with HAL.  Evenything works great, except my mouse moves oddly at times.  I will be moving the mouse around the screen and it will randomly jump around.  Not much, but enough that it makes it difficult to click on links and certain buttons.  I've not worked with the abstraction layer drivers (evdev) before so i really have no idea what could be wrong.  Any help would be great, thanks.

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## VoidMage

Are you sure it's not a hardware failure ?

Short of that dga problem, mouse behaves as it always did, while on desktop.

Perhaps it's something KDE specific (some desktop effects or such).

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## DopplerEffect

It's definately not the mouse because the touchpad malfunctions in the same way, and i don't have any desktop effects running that would affect the mouse (as far as i know).

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## DopplerEffect

I tried the mouse on a windows machine and it worked fine.  I thought that maybe it was interpreting the screen size incorrectly and hence maping the mouse wrong, but that didn't make any different.  I honstly have no idea what's wong...

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## DopplerEffect

anyone?

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## hielvc

Did you update your kernel? It could be the "Processor type and features">Preemption Type and/or Timer Frequency.

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## paulj

I have this problem as well, and arrived at the upgrade kernel option. I have now installed 2.6.28-gentoo-r5, and still appear to have the same problem. It isn't all the time, so I am now monitoring the CPU load to see if it is load related. Regarding the Preemption Type and Timer Frequency - what should they be set to?

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## DopplerEffect

One thing I discovered, is that if you have a optical mouse with a high-definition laser (aka 1000 dpi + ) then there are certain surfaces, such as carpet and other fabrics, that will cause the mouse to move erratically, beyond the ability of the evdev driver to compensate.  It's nothing to do with the software.

Hope this help  :Smile: 

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## hielvc

For Preemption you go to /usr/src/linux <<this should be pointing to your current kernel and run "make xconfig or menuconfig". Step down to :

Processor type and features>>Preemption Model>>Voluntary Kernel Preemption (Desktop)

  or Preemptible Kernel (Low-Latency Desktop) 

For the Timer Frequency ( how often the kernel checks for events such as mouse movement or the keyboard even)

  Processor type and features>>Timer frequency (1000 HZ) Set to 1000 HZ for a desktop, though I'm useing 300 HZ and it is working fine.

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## paulj

 *hielvc wrote:*   

> For Preemption you go to /usr/src/linux <<this should be pointing to your current kernel and run "make xconfig or menuconfig". Step down to :
> 
> Processor type and features>>Preemption Model>>Voluntary Kernel Preemption (Desktop)
> 
>   or Preemptible Kernel (Low-Latency Desktop) 
> ...

 

Already on voluntary Kernel Preemption - will try Low-Latency Desktop option.

 *Quote:*   

> 
> 
> For the Timer Frequency ( how often the kernel checks for events such as mouse movement or the keyboard even)
> 
>   Processor type and features>>Timer frequency (1000 HZ) Set to 1000 HZ for a desktop, though I'm useing 300 HZ and it is working fine.

 

Already set to 1000Hz.

I'll report back when tested.

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## paulj

Early days yet, but I haven't suffered any response issues with the mouse since changing to Preemtable desktop.

Thanks!  :Very Happy: 

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