Small tearing in screen for iMX6

Hi there,

I’ve been setting up the new 800x480 screen with the capacitive touchscreen, but I can see there is a small blinking tear in the screen that doesn’t happen in the VF61. I have yet to confirm this but I think it also happens in the T30. Is very noticeable in the icons and in the subtitule (the board name), and it also happens with the big Toradex logo while loading from U-boot, but is not appreciable while loading the kernel.alt text

I was afraid it had to do with the dts changes I made to get the TS working, but with a fresh image happens as well.

I’ve checked http://developer.toradex.com/knowledge-base/display-output-resolution-and-timings-linux#iMX_6_based_modules without much luck. I’ve been able to extend the screen playing with xrandr and U-boot arguments but it doesn’t solve the issue.

If it helps, this is my xrandr output:

root@colibri-imx6:~# xrandr
Screen 0: minimum 240 x 240, current 640 x 480, maximum 8192 x 8192
DISP3 BG connected 640x480+0+0 (normal left inverted right x axis y axis) 0mm x 0mm
   U:640x480p-59  59.38*+

Maybe it has something to do that it’s not LVDS like the VF61?

Thanks, Álvaro.

Also, I want to point out something from the TS, unrelated to the question:

http://developer.toradex.com/knowledge-base/first-steps-with-capacitive-touch-display-7-inch-parallel#Embedded_Linux

In the DTS, by default, INT and RESET set to SODIMM 107 and 106, while I think in the documentation it’s always referring to SODIMM 28 and 30. I had to make several changes to the atmel_mxt_ts node regarding the interrupts, and change the pinmux in order to use the same pinout than the VF61. I’ve also had to delete the PCAP gpio node since it was already using both pins there, even though I wasn’t using the PCAP.

Also, I think there is an errata in:

To load the driver module use:
modeprobe atmel_mxt_ts

I guess it should be “modprobe”.

Hi

The Capacitive Touch Display 7” Parallel and Resistive Touch Display 7" Parallel need the pixel clock inverted compared to our standard setting.

Try to use the named resolution setting FusionF07A in U-Boot’s vidargs variable as outlined here.

Max

The new displays have a new FFC cable with the touch signals. Currently for Colibri only the Aster board has that connector and there pins 107 and 108 are used.

We are in the process to describe how to connect the displays to the other carrier boards, then with pins 28 and 30. Sorry for the inconvenience.

I’m going to change the modeprobe typo, thanks for pointing it out.

Thanks Max :slight_smile:

setenv vidargs 'video=mxcfb0:dev=lcd,FusionF07A,if=RGB666'
saveenv

worked