Colibri IMX8X RGB


we want to use a 5" 800x480 24bpp RGB Display on the Colibri IMX8DX 1GB V1.0 D.
To use the display with 18bpp we connected the channels R0-1, G0-1, B0-1 to ground.

We applied the following overlays: colibri-imx8x_parallel-rgb_overlay.dtbo colibri-imx8x_ad7879_overlay.dtbo
and also a custom overlay for the display with timings provided from manufacturer:

// Riverdi 5inch display with a resolution of 800x480 pixel. 


/ {
 compatible = "toradex,apalis_imx6q",

&{/panel-dpi} {
 status = "okay";
    width-mm = <108>;
    height-mm = <65>;

 panel-timing {
        clock-frequency = <25000000>;
        hactive = <800>;
        vactive = <480>;
        hsync-len = <4>;
        hfront-porch = <8>;
        hback-porch = <8>;
        vsync-len = <4>;
        vfront-porch = <8>;
        vback-porch = <8>;

Display is working and the console output looks fine except the linux icons:

kmscube and custom app are not rendered correctly.

Rendered 2012 frames in 2.000253 sec (1005.872946 fps)

Custom app:
You can see that some letters are clear and others have little artifacts

Any idea what can be the problem here?

Thanks in advance

Additional information:

# fbset

mode "800x480-0"
        # D: 0.000 MHz, H: 0.000 kHz, V: 0.000 Hz
        geometry 800 480 800 480 32
        timings 0 0 0 0 0 0 0
        accel true
        rgba 8/16,8/8,8/0,0/0

Hi @DrWenz !

From your video, we see some jumpers behind the display

Are those pins in any way related to the data signals for the display?

If yes, could you please test with some proper cable?

Best regards,

Hello @henrique.tx,

the jumpers behind the display only relevant for touch controller, power supply, backlight control and other periphery that is not relevant for the display currently.

What looks strange for me is that kmscube renders at 1000+ fps?

Hi @DrWenz !

Thanks for the information.

Indeed this is also strange.

Turns out that this is a known issue.

Please check TOR-2145 in TorizonCore Issue Tracker and ELB-4203 in Toradex System/Computer on Modules - Linux BSP Release.

Let us know if this helps you.

Best regards,

Hin @henrique.tx,

with the additional overlay it works fine :slight_smile:
Thx for your help!

1 Like

Hi @DrWenz !

Thanks for the feedback!

Best regards,