Linux headers version problem/bug?

Linux headers version problem/bug?

[Alexey Mednyy]

Hello everybody!

Everything started with problematic touchscreen:

We've got mx53 based board. And we're using mc34709 touchscreen on it.
Here is output of xinput_calibrator:
> root@imx53qsb:~# xinput_calibrator -v
> DEBUG: XInputExtension version is 2.3
> DEBUG: Skipping virtual master devices and devices without axis valuators.
> DEBUG: Skipping device 'Virtual core XTEST pointer' id=4, does not
> report Absolute events.
> DEBUG: Selected device: mxc_ts
> DEBUG: Not usbtouchscreen calibrator: Not a usbtouchscreen device
> DEBUG: Read axes swap value of 0.
> DEBUG: Read InvertX=0, InvertY=0.
> Calibrating EVDEV driver for "mxc_ts" id=9
>         current calibration values (from XInput): min_x=0, max_x=0 and
> min_y=0, max_y=0
> DEBUG: Adding click 0 (X=0, Y=0)
> DEBUG: Not adding click 1 (X=0, Y=0): within 7 pixels of previous click
> DEBUG: Not adding click 1 (X=0, Y=0): within 7 pixels of previous click
> DEBUG: Not adding click 1 (X=0, Y=0): within 7 pixels of previous click

And Xorg.log:
> root@imx53qsb:~# tail /var/log/Xorg.0.log
> Divide by Zero in xf86ScaleAxis
> Divide by Zero in xf86ScaleAxis
> Divide by Zero in xf86ScaleAxis
> Divide by Zero in xf86ScaleAxis
> Divide by Zero in xf86ScaleAxis
> Divide by Zero in xf86ScaleAxis
> Divide by Zero in xf86ScaleAxis
> Divide by Zero in xf86ScaleAxis
> Divide by Zero in xf86ScaleAxis
> Divide by Zero in xf86ScaleAxis

But evtest /dev/input/touchscreen0 shows right values:
> Input driver version is 1.0.0
> Input device ID: bus 0x0 vendor 0x0 product 0x0 version 0x0
> Input device name: "mxc_ts"
> Supported events:
>   Event type 0 (Sync)
>   Event type 1 (Key)
>     Event code 330 (Touch)
>   Event type 3 (Absolute)
>     Event code 0 (X)
>       Value    239
>       Min        0
>       Max        0
>     Event code 1 (Y)
>       Value    215
>       Min        0
>       Max        0
>     Event code 24 (Pressure)
>       Value      0
>       Min        0
>       Max        0
> Testing ... (interrupt to exit)
> Event: time 1412607844.642568, type 3 (Absolute), code 0 (X), value 239
> Event: time 1412607844.642581, type 3 (Absolute), code 1 (Y), value 215
X,Y axis values increases\decreases right when I move pointer.

So problem in evdev xinput driver.

However I remember that I used tslib for touchscreen before. And I've
added tslib and xf86-input-tslib to receipt.
And I've seen this:
> root@imx53qsb:~# ts_calibrate /dev/input/event3
> xres = 640, yres = 480
> tslib: Selected device uses a different version of the event protocol
> than tslib was compiled for
We are using custom kernel based on imx_2.6.35_maintain branch, but
yocto produces kernel with same headers that our kernel.
After baking image I just replace uImage of default mx53qsb with mine
and all works fine!
So I'm replacing one 2.6.35 image with another 2.6.35 image. But yocto
compiling software with what? mainline headers or what?
I think that is wrong behavior somewhere in yocto. Why yocto uses wrong
headers?

Re: Linux headers version problem/bug?

[Otavio Salvador]

On Mon, Oct 6, 2014 at 1:11 PM, Alexey Mednyy <swexru@gmail.com> wrote:
...
> So I'm replacing one 2.6.35 image with another 2.6.35 image. But yocto
> compiling software with what? mainline headers or what?
> I think that is wrong behavior somewhere in yocto. Why yocto uses wrong
> headers?
...

Long history short:

Yocto Project builds using linux headers from 3.xx (depending on the branch).

Long history:

Yocto Project builds using a validated version of Linux headers. This
is important to avoid ABI changes between libraries (as does
application and glibc uses the Linux headers to choose runtime
protocols and like).

So the end result is you need to change the input protocol in the
kernel to make it compatible with the newer version provided by newer
kernel. It shouldn't be hard to do. In case you do that, please share
the patch so we apply it on top of the linux-imx recipe and avoid this
issue to other users in future.


-- 
Otavio Salvador                             O.S. Systems
http://www.ossystems.com.br        http://code.ossystems.com.br
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