From johann.obermayr at sigmatek.at  Thu Dec  8 22:13:50 2016
From: johann.obermayr at sigmatek.at (Johann Obermayr)
Date: Thu, 8 Dec 2016 23:13:50 +0100
Subject: 2 equal touches at same time
Message-ID: <69d1039b-3f55-5833-70aa-8785b4ecebab@sigmatek.at>

Hello,

we use version 2.7.3 (yocto). X-Server 1.14.0
we have connect 2 equal touches over usb at your cpu (i.mx6 cpu)

now we see, that evdev_drv mix the events from both touches.

example:
touch two sends
    ABS_X  101
    ABS_Y  100
    BTN_TOUCH 1
    sync

touch one sends
    ABS_X   1000
    ABS_Y    1000
    BTN_TOUCH     1
    sync

touch two sends
    ABS_X  100
    BTN_TOUCH 1
    sync

the function input_handle_abs_event filter double event. so ABS_Y is 
only sent, if it was change.

XEvent
   get not X=100 and Y=1000
    and that is wrong.

does newer verison of evdev_drv solve this problem ?

regards
    Johann

From peter.hutterer at who-t.net  Thu Dec  8 23:58:20 2016
From: peter.hutterer at who-t.net (Peter Hutterer)
Date: Fri, 9 Dec 2016 09:58:20 +1000
Subject: 2 equal touches at same time
In-Reply-To: <69d1039b-3f55-5833-70aa-8785b4ecebab@sigmatek.at>
References: <69d1039b-3f55-5833-70aa-8785b4ecebab@sigmatek.at>
Message-ID: <20161208235820.GB17195@jelly>

Servus :)

On Thu, Dec 08, 2016 at 11:13:50PM +0100, Johann Obermayr wrote:
> Hello,
> 
> we use version 2.7.3 (yocto). X-Server 1.14.0
> we have connect 2 equal touches over usb at your cpu (i.mx6 cpu)
> 
> now we see, that evdev_drv mix the events from both touches.
> 
> example:
> touch two sends
>    ABS_X  101
>    ABS_Y  100
>    BTN_TOUCH 1
>    sync
> 
> touch one sends
>    ABS_X   1000
>    ABS_Y    1000
>    BTN_TOUCH     1
>    sync
> 
> touch two sends
>    ABS_X  100
>    BTN_TOUCH 1
>    sync
> 
> the function input_handle_abs_event filter double event. so ABS_Y is only
> sent, if it was change.
> 
> XEvent
>   get not X=100 and Y=1000
>    and that is wrong.
> 
> does newer verison of evdev_drv solve this problem ?

1.14 is the server version, you'd have to check the actual xf86-input-evdev
version with it. but 1.14 is 3.5 years old too, so it's a bit hard to
remember what got fixed since.

also, this mailing list is for the low-level tools (libevdev, evemu, ...),
evdev is part of the xorg stack so you're better off sending to
xorg-devel at lists.freedesktop.org. It'll still be me answering there ;)

but the touch sequence you outlined above doesn't seem right, it looks like
the kernel send single touch events only? I think this case may be best
filed as a bug against xorg, Input/evdev in bugs.freedesktop.org. Attach the
output from evemu-record for such a touch seqeuence and then we can have a
look at what's going on.

Cheers,
   Peter