On 08/26/2010 06:54 AM, Rafi Rubin wrote: [...] > +Parameters > +---------- > + > +Note: values set at load time are global and will apply to all applicable > +devices. Adjusting parameters with sysfs will override the load time values, > +but only for that one device. > + > +The following parameters are used to configure filters to reduce noise: > + > +activate_slack number of fingers to ignore before processing events > + > +activation_height size threshold to activate immediately > +activation_width > + > +min_height size threshold bellow which fingers are ignored > +min_width both to decide activation and during activity > + > +deactivate_slack the number of "no contact" frames to ignore before > + propagating the end of activity events > + > +When the last finger is removed from the device, it sends a number of empty > +frames. By holding off on deactivation for a few frames we can tolerate false > +erroneous disconnects, where the sensor may mistakenly not detect a finger that > +is still present. Thus deactivate_slack addresses problems where a users might > +see breaks in lines during drawing, or drop an object during a long drag. Without contact tracking, it is hard to imagine activation filtering to work properly. I would advocate to remove this functionality from the driver, and add it in userspace instead. Henrik -- To unsubscribe from this list: send the line "unsubscribe linux-input" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
