On Wed, Apr 14, 2021 at 10:26:13AM -0700, Dmitry Torokhov wrote: > Hi Giulio, Peter, > > On Wed, Apr 14, 2021 at 01:22:55PM +0200, Giulio Benetti wrote: > > Hi Peter, Dmitry, > > > > On 4/14/21 8:46 AM, Peter Hutterer wrote: > > > On Tue, Apr 13, 2021 at 10:44:07PM -0700, Dmitry Torokhov wrote: > > > > Hi Giulio, > > > > > > > > On Tue, Apr 13, 2021 at 04:44:46PM +0200, Giulio Benetti wrote: > > > > > + > > > > > + input_mt_report_pointer_emulation(tsdata->input, true); > > > > > > > > For touchscreens it does not make much sense to report BTN_DOUBLETAP, > > > > BTN_TRIPLETAP, etc, events (they are really for touchpads), so I changed > > > > this to > > > > > > > > input_mt_report_pointer_emulation(tsdata->input, false); > > > > > > > > to only report ABS_X, ABS_Y, and BTN_TOUCH, and applied. > > > > > > Can you expand on this please, just to make sure I'm not misinterpreting > > > those codes? Those bits are just for how many fingers are down (but without > > > position), dropping those bits means you restrict the device to a pure > > > single-touch screen. Or am I missing something here? > > They are indeed represent number of fingers on the surface. I think I > over-simplified this a bit by saying these events are only for > touchpads, as there is allowance for BTN_TOOL_*TAP in > Documentation/input/multi-touch-protocol.rst for MT devices that may > report more contacts than what they can distinctly track, and it is > not restricted to touchpads (but I believe in reality only used by a > couple of "semi-MT" touchpad drivers). fwiw, almost all touchpads on ps2 use that functionality - they can track 2 touchpoints but *detect* up to 5. There's significant insanity in libinput to deal with that because it is so common :) semi-mt is orthogonal to that, it's the an inability to track two touchpoints correctly (only get top-left and bottom-right, but it's guesswork which finger is in which corner). > What I meant to say that for ST fallback of MT-capable devices we > typically provide BTN_TOOL_*TAP for devices declared as INPUT_MT_POINTER > (which is touchpads) and for INPUT_MT_DIRECT and others we only provide > ABS_X, ABS_Y, ABS_PRESSURE and BTN_TOUCH (see input_mt_sync_frame()), > and I think this driver should follow the suit. ah, right. that makes sense, thanks for the clarification. Cheers, Peter
