Verdin imx8mp backlight problem

[khalil.fourati]

Mallow Board v1.1B
verdin Imx8mp 1.1B
Capacitive 10 inch LVDS display from Toradex

hello im trying to activate the 10.1" display from toradex on mallow carrier board
i’ve added verdin-imx8mp-panel-cap-touch-10inch-lvds_overlay.dtbo to the overlays.txt and
setenv fdt_board mallow
setenv variant wifi
setenv fdt_file verdin-imx8mp-wifi-mallow.dtb
however the backlight never works
dmesg returns:
platform 32c00000.bus:ldb@32ec005c: Fixing up cyclic dependency with panel-lvds-native
pwm-backlight backlight-lvds-native: supply power not found using dummy regulator

i tried with the verdin evaluation board with the dsi to lvds adapter and it works right after changing the overlays.txt and updating the environnement variables

[ToradexAI]

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

Did you like my answer?

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Hello,

It seems you’re encountering a backlight issue with your 10.1" LVDS display on the Verdin iMX8MP module with the Mallow carrier board. Let’s address the errors from your dmesg logs:

1. Cyclic Dependency Error: The message “Fixing up cyclic dependency with panel-lvds-native” suggests a potential configuration issue in the device tree. Ensure that the overlay verdin-imx8mp-panel-cap-touch-10inch-lvds_overlay.dtbo is correctly applied and compatible with your setup. Double-check for any misconfigurations or missing dependencies in the overlay file.

2. Dummy Regulator for Backlight: The error “pwm-backlight backlight-lvds-native: supply power not found using dummy regulator” indicates that the backlight power supply is not properly defined. Verify that the power supply for the backlight is correctly specified in your device tree. You may need to add or modify a regulator entry to ensure the backlight receives power.

3. Environment Variables: Confirm that the environment variables for the Mallow board and Wi-Fi variant are correctly set and match your hardware configuration.

4. Comparison with Evaluation Board: Since the setup works on the Verdin evaluation board with the DSI to LVDS adapter, compare the device tree and configuration settings between the two setups. This might help identify any discrepancies or missing configurations on the Mallow board.

By addressing these points, you should be able to resolve the backlight issue. If the problem persists, further investigation into the device tree configuration and hardware connections may be necessary.

Best regards,
Toradex AI Assistant

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

Verdin imx8mp mipi_dsi display weston failure / no image

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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

Guide for setting up LVDS with Colibri imx8x.

[marcioalbano.tx]

Hello Khalil,

First, could you provide more details about which BSP version is being used?
Also, please check if you followed the steps for connecting the display to the Mallow Carrier Board described on the developer website making sure that the JP1 jumper is closed to power the LVDS display backlight through the LVDS connector.

Finally, please confirm if you are using the proper overlay file for each case:

verdin-imx8mp_panel-cap-touch-10inch-dsi_overlay.dtbo for the Mallow Board
verdin-imx8mp_dsi-to-lvds_panel-cap-touch-10inch-lvds_overlay.dtbo for the Verdin Development Board.

Best Regards,
Marcio

[khalil.fourati]

Hello
yes i did close the jumper j1 and the overlay im using for the mallow board is verdin-imx8mp_panel-cap-touch-10inch-lvds_overlay.dtbo
is there anything im missing?

[henrique.tx]

Hi @khalil.fourati!

You informed us via email that another Mallow carrier board worked just fine with the display, right?

So I think we can mark this topic as solved, since the issue was hardware-related.

Best regards,