linux-kernel - Re: [PATCH] CHROMIUM: Input: synaptics - filter out the events with low z values

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite for Android: free password hash cracker in your pocket

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:	Fri, 24 Feb 2012 10:08:35 +0100
From:	"Henrik Rydberg" <rydberg@...omail.se>
To:	Dmitry Torokhov <dmitry.torokhov@...il.com>
Cc:	Daniel Kurtz <djkurtz@...omium.org>,
	Chung-yih Wang <cywang@...omium.org>,
	Alessandro Rubini <rubini@...vis.unipv.it>,
	linux-input@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH] CHROMIUM: Input: synaptics - filter out the events with
 low z values

> > The most striking effect is the ability to better retain a
> > drag. Although the statement was made in light of possible
> > (1-strong,1-weak) packets, it should help in the 2-weak case too.
> 
> The bigger question is why is this needed in kernel. The original
> hysteresis with BTN_TOUCH was done for sole benefit of mousedev so that
> we could allow somewhat better transition from standard PS/2 mode into
> native Synaptics mode with absolute coordinates at time when barely
> anyone had Synaptics X driver installed. This was, what, 10 years ago?

The semi-mt behavior is obviously a special case, where userspace
relies on the reported number of fingers to transition between one
touch and two touches. There is no pressure information sent to
userspace in this case, so the situation is in fact quite similar to
the ancient mousedev situation.

Henrik
--
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/