On Thu, Oct 27, 2016 at 04:46:01PM -0700, Roderick Colenbrander wrote: > On Thu, Oct 27, 2016 at 4:19 PM, Dmitry Torokhov > <dmitry.torokhov@xxxxxxxxx> wrote: > > On Thu, Oct 27, 2016 at 02:31:13PM -0700, Roderick Colenbrander wrote: > >> From: Roderick Colenbrander <roderick.colenbrander@xxxxxxxx> > >> > >> The input-mt driver pointer emulation from 'input_mt_sync_frame' regardless > >> of the flags passed in to 'input_mt_init_slots' by device drivers. > > > > Right, because needing single-touch (pointer) emulation is not property > > of device or driver but rather consumer. If we get to the point where > > everything is ready to accept multi-touch (are we there yet) then we can > > stop doing pointer emulation altogether. > > > >> > >> Pointer emulation is undesired on drivers, which didn't request this > >> capability like the hid-sony driver for the Dualshock 4. This gamepad already > >> reports ABS_X / ABS_Y for gamepad stick purposes. Pointer emulation would > >> inject touchpad values into these sticks, which is undesired. > > > > The driver should not be re-purposing events like that. > > ABS_MT_POSITION_X and ABS_X should match. > > > > Why doesn't driver follow Documentation/input/gamepad.txt? > > > > The original hid-sony code and the multitouch handling code for the Dualshock 4 > were written by the community. We are stepping in to make the hid-sony driver > properly handle the Dualshock 4. > The driver doesn't fully follow the gamepad spec yet, which we will > try to improve. At > least the left analog stick is reported as ABS_X and ABS_Y already, > but the buttons > are inconsistent and right stick is wrong as well. > While it would be great to conform to the spec, the conflict with > multitouch would still > exist as the Dualshock 4 has both analog sticks and a multitouch touchpad. > > Disabling the pointer emulation feature avoids the conflict. This > issue was only exposed > recently by adding of the input_mt_sync_frame call as recommended by Benjamin as > part of some improvements we did for touchpad handling in hid-sony. As I mentioned, ABS_MT_POSITION_X and ABS_X should represent the same data, so the driver's use of them for different sub-devices is not correct. Maybe the multitouch "touchpad" should be reported as completely separate input device and userspace should "stitch" it back into composite device. In any case, as I mentioned above, the pointer emulation is requirement of client and thus this patch is not appropriate. Thanks. -- Dmitry -- 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
