[PATCH] appletouch reports multiple fingers when only one is pressed

Looking at the attachments in this bug report, I noticed that "appletouch.patch" was not flagged as a patch. A patch contains changes to an Ubuntu package that will resolve a bug and this attachment is one! Subsequently, I've checked the patch flag for it. In the future when submitting patches please use the patch checkbox as there are some Launchpad searches that use this feature. You can learn more about patch workflow at https://wiki.ubuntu.com/Bugs/Patches. Thanks for your contribution Jeremy Huddleston!

Hi Jeremy,

Thanks so much for the patch. Just curious if you've also submitted this upstream for consideration? It's a lot of extra work for the Ubuntu kernel team to maintain out of tree patches so as such they typically prefer for patches to be accepted upstream first. To submit the patch upstream please send it to:

<email address hidden>

Also be sure to CC the maintainer, Johannes Berg at <email address hidden> . Thanks.

I did send it to Jason Parekh (jasonparekh at nospam gmail.com) who
was the one who wrote the original code.

I have not sent it to linux-input.

On May 4, 2009, at 17:36, Leann Ogasawara wrote:

> Hi Jeremy,
>
> Thanks so much for the patch. Just curious if you've also submitted
> this upstream for consideration? It's a lot of extra work for the
> Ubuntu kernel team to maintain out of tree patches so as such they
> typically prefer for patches to be accepted upstream first. To submit
> the patch upstream please send it to:
>
> <email address hidden>
>
> Also be sure to CC the maintainer, Johannes Berg at
> <email address hidden> . Thanks.
>
> ** Changed in: linux (Ubuntu)
> Status: New => Incomplete
>
> --
> [PATCH] appletouch reports multiple fingers when only one is pressed
> https://bugs.launchpad.net/bugs/371574
> You received this bug notification because you are a direct subscriber
> of the bug.
>
> Status in “linux” source package in Ubuntu: Incomplete
>
> Bug description:
> Binary package hint: kernel-package
>
> This issue affects atleast jaunty and karmic. The patch is against
> current karmic.
>
> The appletouch driver is prone to reporting multiple fingers when
> only one is
> pressing. The appletouch driver queries an array of pressure
> sensors and
> counts local maxima in pressure to determine the number of fingers.
> It just
> does this on the raw values, so a data stream like:
>
> 0 100 250 300 299 300 250 100 0
>
> actually registers as 2 fingers.
>
> This patch updates the logic to ignore small dips in pressure that
> are less
> than the threshold.

BTW, I did sent it to linux-input.

This patch should be in 2.6.31 http://www.spinics.net/lists/linux-input/msg03595.html

The patch is now in 2.6.31-rc1

Jeremy,

Thanks so much for working to get this into upstream. The Karmic 9.10 kernel will target the upstream 2.6.31 kernel and was most recently rebased with the upstream 2.6.31-rc2 kernel. And indeed looking at the git tree for karmic I see this patch has been merged. I'll paste the commit id below. Alpha images for Karmic are available for testing at http://cdimage.ubuntu.com/daily-live/current/ . Thanks!

ogasawara@emiko:~/ubuntu-karmic$ git log 05e882f890038c702a4f15d385135d03cf74ad48
commit 05e882f890038c702a4f15d385135d03cf74ad48
Author: Jeremy Huddleston <email address hidden>
Date: Wed Jun 3 07:29:39 2009 -0700

    Input: appletouch - improve finger detection

    The appletouch driver is prone to reporting multiple fingers when only
    one is pressing. The appletouch driver queries an array of pressure
    sensors and counts local maxima in pressure to determine the number of
    fingers. It just does this on the raw values, so a data stream like:

    0 100 250 300 299 300 250 100 0

    actually registers as 2 fingers.

    This patch updates the logic to ignore small dips in pressure that are
    less than the threshold.

    Signed-off-by: Jeremy Huddleston <email address hidden>
    Signed-off-by: Dmitry Torokhov <email address hidden>