First impressions of joyride-2280

Richard A. Smith richard at laptop.org
Mon Aug 11 17:36:48 EDT 2008


Ton van Overbeek wrote:


> - The polling of the EC every 30 seconds has disappeared.  At least
>   it does not show up in the dmesg output.
> - More important, the touchpad seems to behave much better. May be
>   related to the reduced polling of the EC.

That makes sense if previously you were seeing jumpy touchpad behavior 
every 30 seconds or so.  During EC command processing the kernel 
disables interrupts which means that you won't be responding to data 
from the touchpad.  The update rate for the touchpad is 12ms so if you 
hang out for longer than 12 ms we think you lose motion data.  I don't 
know how deep the buffer is on the touchpad but it does not seem to be 
very deep.  The EC only buffers a single byte.

-- 
Richard Smith  <richard at laptop.org>
One Laptop Per Child



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