On Fri, Feb 24, 2012 at 01:16:02AM -0800, Dmitry Torokhov wrote: > On Fri, Feb 24, 2012 at 01:14:52AM -0800, Dmitry Torokhov wrote: > > On Fri, Feb 24, 2012 at 10:08:35AM +0100, Henrik Rydberg wrote: > > > > > The most striking effect is the ability to better retain a > > > > > drag. Although the statement was made in light of possible > > > > > (1-strong,1-weak) packets, it should help in the 2-weak case too. > > > > > > > > The bigger question is why is this needed in kernel. The original > > > > hysteresis with BTN_TOUCH was done for sole benefit of mousedev so that > > > > we could allow somewhat better transition from standard PS/2 mode into > > > > native Synaptics mode with absolute coordinates at time when barely > > > > anyone had Synaptics X driver installed. This was, what, 10 years ago? > > > > > > The semi-mt behavior is obviously a special case, where userspace > > > relies on the reported number of fingers to transition between one > > > touch and two touches. There is no pressure information sent to > > > userspace in this case, so the situation is in fact quite similar to > > > the ancient mousedev situation. > > > > We still report ABS_PRESSURE but maybe we should report ABS_MT_PRESSURE > > as well? > > BTW, the reason I do not like this in kernel is because it dos not allow > users control touchpad sensitivity. ...which is perfectly reasonable, I agree. OTOH, the semi-mt devices tend to report close-to-bogus information for anything related to individual touches. Pressure is sadly no different, as Daniel pointed out. I don't know what is the lesser evil here. 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
