i.MX ProcessorsのトピックRe: Pixel distortion with X11

Pixel distortion with X11

philippt85 — Sun, 12 Apr 2015 07:57:55 GMT

I have board with i.MX6 cpu and 7" lcd display, connected as parallel rgb (18-bit).

When i run the vivante samples as native open gl with framebuffer, it's all ok. The samples where shown on the display as expected.

But when I try to work with the X11 server i get heavy pixel distortion. It looks like the bpp used by X11 does not match the bpp of the lcd.

I tried already to change the 'DefaultDepth' value in the xorg.conf, but with no success.

The same problems appear in Yocto (Dora) with X-server version 1.14 and Ubuntu 12.04 with X-sever vesrion 1.11.

Also the distortion is not static, the pixels are flickering.

Below you see an picture of what i mean. The background should be a simple linear gradient from red to green.

I think it's a problem with the X-server because if i stop the server (for Example with 'service lightdm stop' in Ubuntu) the distortion stops and the background is shown as a smooth gradient.

It affects not only the background, also the icons, scrollbars, borders, etc.

Does anyone has an idea to solve this?

Re: Pixel distortion with X11

igorpadykov — Mon, 13 Apr 2015 07:41:13 GMT

HI Philipp

I would sggest try new BSP with GPU driver upgraded to Vivante v5.0.11p4.4.

L3.14.28_1.0.0_iMX6QDLS_BUNDLE : i.MX 6Quad, i.MX 6Dual, i.MX 6DualLite,

i.MX 6Solo Linux Binary Demo Files and Linux BSP

Best regards

igor

Re: Pixel distortion with X11

philippt85 — Mon, 13 Apr 2015 08:26:35 GMT

Hi Igor,

i can't switch to a newer BSP. I have to use a given kernel which is a 3.0.35 with support for vivante 4.6.9p12.

I also tried software rendering for X11, with the same result...