I have a custom Baseboard with Verdin IMX8MP and want to use native LVDS and HDMI Display Interface. Both Interfaces work fine, if I just activate one of them in devicetree.
When I try to use both I get following message at boot time repeating endless:
I think this should work on Verdin Development Board with Verdin iMX8M Plus Mezzanine board. I do not have these boards, but when I tried with (unmodified) Toradex Multimedia Reference Image, just activating “verdin-imx8mp_mezzanine_panel-cap-touch-10inch-lvds_overlay.dts” and “verdin-imx8mp_hdmi_overlay.dts” overlays and got the same endless boot message.
Has anyone worked with this configuration on Verdin Development Board before? Does it work at all? Otherwise must be a problem with my Hardware or modified Toradex Multimedia Reference Image…
I have tested the following setup and it works without issues
Verdin Development board 1.1C
Verdin iMX8M Plus Quad 4GB WB IT V1.0C
Reference Multimedia image 6.2.0
Which HDMI display and LVDS screen do you use?
Could you send us the full dmesg output when you use both screens at the same time?
Is it possible for you to share with us the schematics of your custom carrier board? You can send them to firstname.lastname@example.org, mentioning this topic.
Thanks for your help. Good to hear that this works on Develoment-Board.
As I don’t have the development board, I tried with Dahlia-Board (I know native LVDS is not connected there). I can reproduce the same problem on dahlia board ( V1.1.C ) with unmodified Reference Multimedia image 6.2.0 on Verdin iMX8M Plus Quad 4GB WB IT V1.0D. When I activate “verdin-imx8mp_mezzanine_panel-cap-touch-10inch-lvds_overlay.dts” and “verdin-imx8mp_hdmi_overlay.dts" in overlays.txt the endless repeating message is appearing (boot_log.txt (23.8 KB)). When using only one of the overlays, everything is booting fine.
The problem appears with no Display connected, so I think Displays are not relevant.
I can send our schematics if you want, but if you can reproduce with Dahlia-Board, I think thats not necessary.
I think there is some confugration in Devicetree-Overlays that works on Development-Board Hardware but has conflicts on Dahlia-Board. (only when using both of the overlays !?!)
The problem here is that you use a device tree that is not compatible with your carrier board, so the behavior is not defined.
Could you please send us the schematics of your custom carrier board, so we can see how similar your native LVDS implementation is compared to the Verdin development board + mezzanine?
You can send the schematics to email@example.com, mentioning the subject of this thread.
After a more detailed analysis I realized that the problem also occurs with the Verdin development board.
I didn’t see it before because I had enabled the DSI to HDMI overlay verdin-imx8mp_dsi-to-hdmi_overlay.dtbo ( although it was not needed).
Can you enable this overlay and see if this solves your issue? Although this isn’t an elegant solution, it can be a temporary workaround while we figure out the root cause of this behavior.
yes, as a workarround this worked on my custom hardware too!
Now I will try to find the devicetree node in “verdin-imx8mp_dsi-to-hdmi_overlay.dtsi” , which was missing, and add this node to my custom overlay. Otherwise I will get another conflict, because we use some DSI pins as GPIO on custom board.