linux-kernel - Re: [PATCH 1/4] Adding documention

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]

Message-ID: <4C77AA45.4030805@euromail.se>
Date:	Fri, 27 Aug 2010 14:06:29 +0200
From:	Henrik Rydberg <rydberg@...omail.se>
To:	Rafi Rubin <rafi@...s.upenn.edu>
CC:	jkosina@...e.cz, linux-input@...r.kernel.org,
	linux-kernel@...r.kernel.org, dmitry.torokhov@...il.com,
	chatty@...c.fr, micki@...rig.com
Subject: Re: [PATCH 1/4] Adding documention

On 08/26/2010 06:54 AM, Rafi Rubin wrote:

[...]

> +Parameters

> +----------
> +
> +Note: values set at load time are global and will apply to all applicable
> +devices.  Adjusting parameters with sysfs will override the load time values,
> +but only for that one device.
> +
> +The following parameters are used to configure filters to reduce noise:
> +
> +activate_slack		number of fingers to ignore before processing events
> +
> +activation_height	size threshold to activate immediately
> +activation_width
> +
> +min_height		size threshold bellow which fingers are ignored
> +min_width		both to decide activation and during activity
> +
> +deactivate_slack	the number of "no contact" frames to ignore before
> +			propagating the end of activity events
> +
> +When the last finger is removed from the device, it sends a number of empty
> +frames.  By holding off on deactivation for a few frames we can tolerate false
> +erroneous disconnects, where the sensor may mistakenly not detect a finger that
> +is still present.  Thus deactivate_slack addresses problems where a users might
> +see breaks in lines during drawing, or drop an object during a long drag.


Without contact tracking, it is hard to imagine activation filtering to work
properly. I would advocate to remove this functionality from the driver, and add
it in userspace instead.

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/