LVDS with mallow Carrier Board

[Seyad]

I’m using the Verdin iMX 8M Plus with the Mallow carrier board, trying to get a 10-inch LVDS display from Toradex working. I’m running a customized Yocto image and have added the following overlays:

cat /boot/overlays.txt
fdt_overlays=verdin-imx8mp_panel-cap-touch-10inch-lvds_overlay.dtbo verdin-imx8mp_spidev_overlay.dtbo

However, I’m encountering errors in the dmesg output related to the LVDS display:

[ 0.318092] platform 32c00000.bus:ldb@32ec005c: Fixing up cyclic dependency with panel-lvds-native
[ 1.462658] pwm-backlight backlight-lvds-native: supply power not found, using dummy regulator

Any guidance on resolving these errors or configuring the LVDS setup correctly would be greatly appreciated!

[ToradexAI]

Hi, I’m the Toradex AI Assistant. The Toradex Support team will follow up with you shortly!

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Based on the context provided, here are some steps you can take to resolve the issues with your LVDS display setup on the Verdin iMX 8M Plus with the Mallow carrier board:

1. Cyclic Dependency:

   • Review the device tree overlays you are using, specifically verdin-imx8mp_panel-cap-touch-10inch-lvds_overlay.dtbo and verdin-imx8mp_spidev_overlay.dtbo. Check for any circular references or misconfigurations that could be causing the cyclic dependency error. You may need to adjust the order of the overlays or modify their definitions to resolve the conflict.

2. Missing Power Supply:

   • Verify that the power supply for the backlight is correctly defined in the device tree. Ensure that the necessary power regulators are specified and that the connections are properly made on the Mallow carrier board. The warning about using a dummy regulator suggests that the system cannot find the specified power supply, so double-check the device tree configuration for any missing or incorrect entries related to the backlight power supply.

3. Consult Documentation:

   • Refer to the Toradex documentation for the specific LVDS display and the Mallow carrier board. This may provide insights into required configurations and troubleshooting steps that are specific to your hardware setup.

4. Examine dmesg Output:

   • Continue to monitor the dmesg output for any additional error messages that may provide further clues about the configuration issues. Addressing these messages systematically can help in resolving the overall setup problems.

By following these recommendations, you should be able to address the errors and configure the LVDS display correctly.

Please, also check if these links can help you solve your problem:

Verdin iMX8m plus two LVDS display support

Hi there, I would like to know if DSI/LVDS bridge IC is required to support two separate LVDS displays in Verdin iMX8m plus. In the data sheet, it is not stated that the LVDS I/F in the SoM supports two independent single channels. But the block diagram in the date sheet implies that 2 single LVDS channels are supported. Please let me know which one is correct.

Enable 10.1" LVDS display on Mallow carrier board

SOM: Verdin iMX8M Plus Board: Mallow Display: Toradex 10.1" LVDS Torizon: Newest Hello I’m trying to activate the Toradex 10.1" display on a Mallow carrier board but can’t get any further in the instructions: Which device tree overlay should I load to activate the display? I did this with an Apalis iMX6 and a Ixora Carrier Board and it worked. But I don’t find an example for the Mallow carrier board. Regarding to Toradex sales it should work out of the box. Thanks

How to activate the LVDS touch panel for Verdin iMX8M Mini on Yocto.

[lucas_az.tx]

Hi @Seyad!

As I said in this topic, the jumper JP1 must be closed. If it is open, the backlight converter will not be powered, and you’ll see nothing on the display.

Could you test it, please?

Best regards.
Lucas Azeituno

[Seyad]

Thank you for your help! @lucas_az.tx I finally found the issue. I had used a 24-volt power supply for the Mallow carrier board, which was directly passed to the display, causing it not to work. After switching to a 12-volt power supply, everything is now working fine.

[lucas_az.tx]

Hi @Seyad!

I’m glad to hear that it worked.

Best regards.
Lucas Azeituno