Re: [PATCH 4/4] input - wacom: Support 2FGT in MT format

quoted

quoted

+static int wacom_tpc_mt_touch(struct wacom_wac *wacom)
+{
+     struct input_dev *input = wacom->input;
+     unsigned char *data = wacom->data;
+     int i;
+
+     if (wacom->shared->stylus_in_proximity && !wacom->shared->touch_down)
+             return 0;

Seeing one case handled out of four possible always makes me nervous.

The above statement is to avoid going through the input_mt_slot and
input_mt_report_slot_state routines without posting any meaningful
events. I guess it could be considered as a performance enhancement?

It won't be posting events unless something changed.

Which case makes you nervous? I'll take care of it ;).

Well, removing the logic above would suffice. :-)

quoted

So only false->true is possible here.

Yeah, both are bools. What else can they take?

Only the transition false-to-true, that is.

quoted

What I can see from the patchset, only wacom_tpc_single_touch() will ever set touch_down to
false. Is that sufficient?

No,  wacom_tpc_mt_touch can set touch_down to false too. When touch is
false, touch_down will be false. This happens when pen in prox or when
both fingers are up.

Now, that is what cannot happen, because of the max() function.
 

Where else do you see it can be changed? tpc_pen() can not do that
since it is on a different port, that's the reason of touch_down.

Thanks,
Henrik
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