linux-kernel - Re: [PATCH 5/6 v2] HID: magicmouse: enable Magic Trackpad support

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: Windows password security audit tool. GUI, reports in PDF.

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

Message-ID: <1283299695.13785.16.camel@graviton>
Date:	Tue, 31 Aug 2010 20:08:15 -0400
From:	Michael Poole <mdpoole@...ilus.org>
To:	Chase Douglas <chase.douglas@...onical.com>
Cc:	Jiri Kosina <jkosina@...e.cz>,
	Henrik Rydberg <rydberg@...omail.se>,
	Tejun Heo <tj@...nel.org>, linux-input@...r.kernel.org,
	linux-kernel@...r.kernel.org
Subject: Re: [PATCH 5/6 v2] HID: magicmouse: enable Magic Trackpad support

On Tue, 2010-08-31 at 14:41 -0400, Chase Douglas wrote:
> The trackpad speaks a similar, but different, protocol from the magic
> mouse. However, only small code tweaks here and there are needed to make
> basic multitouch work.
> 
> Extra logic is required for single-touch emulation of the touchpad. The
> changes made here take the approach that only one finger may emulate the
> single pointer when multiple fingers have touched the screen. Once that
> finger is raised, all touches must be raised before any further single
> touch events can be sent.
> 
> Sometimes the magic trackpad sends two distinct touch reports as one big
> report. Simply splitting the packet in two and resending them through
> magicmouse_raw_event ensures they are handled properly.
> 
> I also added myself to the copyright statement.
> 
> Signed-off-by: Chase Douglas <chase.douglas@...onical.com>
> ---
>  drivers/hid/hid-core.c       |    1 +
>  drivers/hid/hid-ids.h        |    1 +
>  drivers/hid/hid-magicmouse.c |  229 ++++++++++++++++++++++++++++++++----------
>  3 files changed, 176 insertions(+), 55 deletions(-)

Acked-by: Michael Poole <mdpoole@...ilus.org>

One behavior that slightly surprised me -- which I believe is a quirk
due to userspace not expecting touchpads to have button switches -- is
that touches on the trackpad that do not close the switch can still be
interpreted by X as clicks.

Once the discussions about if/how to tweak this code settle down, I'll
put together a patch to change the "down" and "last_up" logic as I
suggested earlier.

Michael Poole

--
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/