How set Display setting imx7d torizon colibri-imx7_panel-res-touch-7inch_overlay

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Hello! Thanks for sharing detailed logs and configuration. Let’s address the issues step by step.

Problem Analysis

Your dmesg shows these errors:

panel-simple panel-dpi: Specify missing bus_format
panel-simple panel-dpi: Expected bpc in {6,8} but got: 0

This means the display subsystem is not correctly receiving the bus_format and bits-per-color (bpc) values.

1. Bus Format

You have:

bus-format = <0x1018>; // MEDIA_BUS_FMT_RGB666_1X18

But this is sometimes not parsed correctly. You should use the string notation for data-mapping, which is more reliable.

Recommended setting:

data-mapping = "vesa-24";

Or, if your display truly requires 18-bit (666), you can try "jeida-18" or "vesa-18". For most 24-bit panels, "vesa-24" is standard.

2. Bits Per Pixel

The error Expected bpc in {6,8} but got: 0 means the “bits-per-pixel” property is missing. The value should match your color depth (typically 24 for 8bpc x 3 colors, or 18 for 6bpc x 3):

bits-per-pixel = <24>;

For 18bpp, use <18>.

3. Example Panel Node

Combine the recommendations as follows:

&panel_dpi {
    status = "okay";
    compatible = "panel-dpi";
    width-mm = <154>;
    height-mm = <86>;

    data-mapping = "vesa-24";           // for 24-bit RGB
    bus-width = <24>;                   // match with data-mapping
    bits-per-pixel = <24>;              // match color depth

    panel-timing {
        clock-frequency = <25175000>;
        hactive = <800>;
        vactive = <480>;
        hsync-len = <128>;
        hback-porch = <88>;
        hfront-porch = <40>;
        vsync-len = <2>;
        vback-porch = <33>;
        vfront-porch = <10>;
        hsync-active = <0>;
        vsync-active = <0>;
        de-active = <1>;
        pixelclk-active = <0>;
    };
};

If using 18-bit data mapping:

data-mapping = "vesa-18";
bus-width = <18>;
bits-per-pixel = <18>;

4. Rebuild and Apply Changes

  • Rebuild your device tree overlay after making these changes.
  • Reapply the overlay and reboot.
  • Check dmesg again for errors.

5. Additional Resources

For more details, refer to:
https://community.toradex.com/t/dual-channel-lvds-dts-overlay-and-display-power-on-sequence-configuration/27731

Next Steps

  1. Correct your overlay as above.
  2. Rebuild/redeploy it.
  3. Reboot and check dmesg | grep panel to see if errors are gone.

If you still have display issues after correcting these properties, please upload your new dmesg output so we can help further.

Best regards, Toradex AI Assistant.