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Date: Wed, 13 Feb 2013 20:27:15 -0800 From: Dmitry Torokhov <dmitry.torokhov@...il.com> To: Daniel Kurtz <djkurtz@...omium.org> Cc: Henrik Rydberg <rydberg@...omail.se>, Seth Forshee <seth.forshee@...onical.com>, Benjamin Herrenschmidt <benh@...nel.crashing.org>, Chung-Yih Wang <cywang@...omium.org>, Chase Douglas <chase.douglas@...onical.com>, linux-input@...r.kernel.org, linux-kernel@...r.kernel.org Subject: Re: [PATCH] Input: synaptics - fix 1->3 contact transition reporting On Fri, Feb 01, 2013 at 04:29:00PM +0800, Daniel Kurtz wrote: > Investigating the following gesture highlighted two slight implementation > errors with choosing which slots to report in which slot when multiple > contacts are present: > > Action SGM AGM (MTB slot:Contact) > 1. Touch contact 0 (0:0) > 2. Touch contact 1 (0:0, 1:1) > 3. Lift contact 0 (1:1) > 4. Touch contacts 2,3 (0:2, 1:3) > > In step 4, slot 1 was not being cleared first, which means the same > tracking ID was being used for reporting both the old contact 1 and the > new contact 3. This could result in "drumroll", where the old contact 1 > would appear to suddenly jump to new finger 3 position. > > Similarly, if contacts 2 & 3 are not detected at the same sample, step 4 > is split into two: > > Action SGM AGM (MTB slot:contact) > 1. Touch contact 0 (0:0) > 2. Touch contact 1 (0:0, 1:1) > 3. Lift contact 0 (1:1) > 4. Touch contact 2 (0:2, 1:1) > 5. Touch contact 3 (0:2, 1:3) > > In this case, there was also a bug. In step 4, when contact 1 moves from > SGM to AGM and contact 2 is first reported in SGM, slot 0 was actually > empty. So slot 0 can be used to report the new SGM (contact 0), > immediately. Since it was empty, contact 2 in slot 0 will get a new > tracking ID. > > Signed-off-by: Daniel Kurtz <djkurtz@...omium.org> Applied, thank you Daniel. -- Dmitry -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@...r.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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