Touchscreen troubles

[Petr Štetiar]

Petr Štetiar <ynezz at true.cz> [2009-12-11 22:41:18]:

> Hi,
> 
> I'm trying to get working 22" resistive 5-wire touchscreen with USB
> controller, it's ET&T TC5UH[1]. I'm using Ubuntu 9.04 with Xorg server 1.6.0,
> evdev version 2.3.2 compiled manualy. I've set calibration[1] gathered using
> values from kernel printk. It kind of works, but only on half of the screen,
> top-lef part:
> 
> <crappy-ascii-art>
> 
>        [x=284; y=279]      [x=1846; y=230]          [x=3633; y=189]
> 		 +-----------------+-------------------+
> 		 |                                .  / |
> 		 |                           .  /      |
> 		 |  working part         . /           |
> 		 |                   . /               |
> [x=209; y=1914]  +               . + [x=1352; y=1697]  + [x=2697; y=1212]
> 		 |           . /                       |
> 		 |       . /          not working      |
> 		 |   . /              part             |
> 		 | /                                   |
> 		 +-----------------+-------------------+
>        [x=165; y=3652]      [x=875; y=3023]        [x=1693; y=2136]
> 
> </crappy-ascii-art>
> 
> If I touch bottom-right corner I get from kernel driver x=1685, y=2220 and
> from xidump x=1785, y=2383 and it seems like almost correct values, but cursor
> is moving only in top-left part, near middle of the screen. I tried without
> calibration values also, swapping axes, but I can't get it working. For me, it
> seems, that the kernel reported and evdev reported values are correct, but
> it's then wrongly interpreted somewhere in Xorg code, and pointer doesn't move
> correctly.

Ok, I've added verbose debug code into xserver and here is what I've observed
so far(sorry, it's not linewrapped, but it should be more readable):

---- [start of log] ------------------------------------------------------------------------------

Touchscreen "calibrated" with:
------------------------------
	Evdev Axis Calibration (225):		66, 2933, 45, 3257

Touch in top-right corner:
--------------------------

	kernel:
	~~~~~~~
	[100077.271713] tc5uh x: 3639 y: 198 touch: 1)

	xserver:
	~~~~~~~~
	(II) evdev: touchscreen: num_valuators: 2 x: 4095 y: 181
	(II) [!] XINPUT: called with x: 4095 y: 181 num: 2.
	(II) [!] XINPUT: pointer is absolute.
	(II) [!] XINPUT: have XFreeXDGA.
	(II) [!] XINPUT: if (num_valuators >= 1 && first_valuator <= 1) {
	(II) [!] XINPUT: if (first_valuator == 0) dx is now: 4095
	(II) [!] XINPUT: if (is_absolute) { dx is now: 2 last.valuators[0]=4093
	(II) [!] XINPUT: if (first_valuator == 1 || num_valuators >= 2) dy is now: 181
	(II) [!] XINPUT: if (is_absolute) { dy is now: -7 last.valuators[1]=188
	(II) [!] XINPUT: before if (DGAStealMotionEvent(device, index=0, dx=2, dy=-7)) { return; }
	(II) [!] DGA: DGAStealMotionEvent called with index=0, dx=2, dy=-7));
	(II) [!] DGA: no direct mode.
	(II) [!] XINPUT: GetPointerEvents() x: 4095 y 181 num: 2.
	[!] DIX: GetPointerEvents() called with num_valuators: 2 x: 4095 y: 181
	[!] DIX: GetPointerEvents() continues...
	[!] DIX: GetPointerEvents() calling moveAbsolute with num_valuators: 2 x: 4095 y: 181 screen: 1680x1050
[1]	[!] DIX: GetPointerEvents() before getValuatorEvents num_valuators: 2 x: 4093 y: 181 root_x: 1679 root_y: 46

Touch in bottom-right corner:
-----------------------------

	kernel:
	~~~~~~~
	[99979.098016] tc5uh x: 1686 y: 2233 touch: 0)

	xserver:
	~~~~~~~~
	(II) evdev: touchscreen: num_valuators: 2 x: 2311 y: 2794
	(II) [!] XINPUT: called with x: 2311 y: 2794 num: 2.
	(II) [!] XINPUT: pointer is absolute.
	(II) [!] XINPUT: if (num_valuators >= 1 && first_valuator <= 1) {
	(II) [!] XINPUT: if (first_valuator == 0) dx is now: 2311
	(II) [!] XINPUT: if (is_absolute) { dx is now: -1782 last.valuators[0]=4093
	(II) [!] XINPUT: if (first_valuator == 1 || num_valuators >= 2) dy is now: 2794
	(II) [!] XINPUT: if (is_absolute) { dy is now: 2613 last.valuators[1]=181
	(II) [!] XINPUT: before if (DGAStealMotionEvent(device, index=0, dx=-1782, dy=2613)) { return; }
	(II) [!] DGA: DGAStealMotionEvent called with index=0, dx=-1782, dy=2613));
	(II) [!] DGA: no direct mode.
	(II) [!] XINPUT: GetPointerEvents() x: 2311 y 2794 num: 2.
	[!] DIX: GetPointerEvents() called with num_valuators: 2 x: 2311 y: 2794
	[!] DIX: GetPointerEvents() continues...
	[!] DIX: GetPointerEvents() calling moveAbsolute with num_valuators: 2 x: 2311 y: 2794 screen: 1680x1050
[2]	[!] DIX: GetPointerEvents() before getValuatorEvents num_valuators: 2 x: 2311 y: 2794 root_x: 948 root_y: 716

---- [end of log] ------------------------------------------------------------------------------

Comments:
~~~~~~~~~
1. Correct behavior: root_x is 100% correct, root_y is off by 46 points, but this can be tweaked by calibration value
2. Wrong behavior: root_x should be same as in [1] about 1679 points, and root_y should be aroung 1050 points but is
   half of the value only, 716 points

Does this shed some more light into my issue?

-- ynezz