Messages in this thread | | | Date | Mon, 24 May 2010 11:13:43 -0700 | From | Dmitry Torokhov <> | Subject | Re: [PATCH 2/2] input: mt: Document the MT event slot protocol (rev4) |
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On Mon, May 24, 2010 at 08:02:40PM +0200, Henrik Rydberg wrote: > Ping Cheng wrote: > > On Mon, May 24, 2010 at 12:13 AM, Henrik Rydberg <rydberg@euromail.se> wrote: > >> Ping Cheng wrote: > >>> What I am thinking is that we only need one SYN_ call for both _MT_ > >>> and regular data combined, which is a call to input_sync() at the end > >>> of the whole packet. The SYN_MT_ can be replaced by the following > >>> example, which I think is more "client-friendly". This solution is > >>> based on the fact that the major difference between type A and type B > >>> is whether we need to filter the data or not: > >>> > >>> ABS_MT_RANDOM 0 > >>> ABS_MT_POSITION_X x[0] > >>> ABS_MT_POSITION_Y y[0] > >>> ABS_MT_ RANDOM 1 > >>> ABS_MT_POSITION_X x[1] > >>> ABS_MT_POSITION_Y y[1] > >>> SYN_REPORT > >>> > >>> input_set_abs_params(input_dev, ABS_MT_RANDOM, 0, 2, 0, 0); > >>> > >>> would tell the clients that they can expect two random touches. > >> And if you do s/RANDOM/SLOT/, you end up with what? ;-) > > > > Haha, I know what you are thinking :). > > > > Maybe I didn't make my point clear. I didn't mean to make SLOT > > backward compatible. I meant to replace SYN_MT_REPORT event with the > > ABS_MT_ RANDOM label so we only sync the whole packet once at the end. > > This way both types of MT_ data follow the same input event reporting > > flow.... > > You mean changing the type A protocol, breaking the current code base? That is a > big no-no. >
We, however, could say that SYN_MT_REPORT may be omitted by the drivers using slotting mechanism.
-- Dmitry
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