Re: synaptics mouse jitter in 2.6.0

[Andres Salomon <dilinger@voxel.net>]

On Tue, 23 Dec 2003 02:41:49 -0500, Dmitry Torokhov wrote:

> On Monday 22 December 2003 10:38 pm, Dmitry Torokhov wrote:
>> On Monday 22 December 2003 09:40 pm, Thomas Molina wrote:
>> > I am running Fedora Core 1 updated on a Presario 12XL325 laptop.  For
>> > a long time during the 2.5 series I couldn't use the synaptics
>> > support. As a result, I haven't tested this for some time.  I just
>> > compiled a fresh 2.6.0 tree, included synaptics support and now I am
>> > getting mouse jitter.
>> >
> <..SKIP..>
>>
>> Right, I think I see it. The mousedev module does not do any smoothing
>> of the reported coordinates which would cause the jitter you are
>> seeing. Normally drivers do 3- or 4-point average.
>>
>> I'll cook up something to fix it. Meanwhile could you give a try Peter
>> Osterlund XFree86 Synaptics driver:
>> http://w1.894.telia.com/~u89404340/touchpad/index.html
>>
> 
> OK, here it is. It will apply against 2.6.0 although will complain about
> some offsets as I have extra stuff in my tree...
> 
> Dmitry
> 
[...]

This works a lot better than both -mm1 and stock 2.6.0's mouse behavior
for me; 2.6.0 likes to drop packets inside the interrupt handler and make
the mouse jump to the edge of the screen, and 2.6.0-mm1 likes to move the
pointer between the time I take my finger off the touchpad and hit the
mouse button.  This appears to fix both issues; however, I still see the
following in logs:

Dec 23 03:33:53 spiral kernel: Synaptics driver lost sync at byte 4
Dec 23 03:33:53 spiral kernel: Synaptics driver lost sync at byte 1
Dec 23 03:33:53 spiral kernel: Synaptics driver resynced.
Dec 23 03:33:55 spiral kernel: Synaptics driver lost sync at byte 1
Dec 23 03:33:55 spiral last message repeated 4 times
Dec 23 03:33:55 spiral kernel: Synaptics driver resynced.