Re: [PATCH] hid-multitouch: fix broken eGalax

From: Henrik Rydberg
Date: Sun Jun 12 2011 - 17:08:19 EST


Hi Benjamin,

> >> With this patch, the detection is made only when the field ContactID
> >> has been detected inside the collection.
> >
> > The patch introduces an order dependence by relying on ContactID
> > occuring early on, which seems unnecessary. How about checking for the
> > presence of ContactID instead, and simply modify the logic which uses
> > last_field_index and last_slot_field?
>
> That's exactly what it does. A touch report has to contain the
> contactID field. And each touch is at least in one collection (some
> devices send one touch per collection, others only one collection for
> the whole report).
> The idea is when hardware makers introduce several input mode for
> their device, they has to put them in different collections.

Ah, right you are, the ensured presence of ContactID is enough to
prove that the patch code is equivalent.

> The logic behind the last_field_index and last_slot_field are only for
> multitouch. So it does not matter if the contactID comes first or last
> in the collection, it will set the right index/field.

Thanks for the clarification.

Reviewed-by: Henrik Rydberg <rydberg@xxxxxxxxxxx>

Cheers,
Henrik
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