DK2 output goes to HDMI and not to DSI display

[AndreyN]

Hi Folks,

I am building openstlinux-weston/st-image-weston image for stm32mp157c-dk2 board using newest Yocto distribution provided by STM. Everything works fine except the output goes always to HDMI (even if no cable attached). I can see bootloader splash image on DSI display. However, after couple of seconds it disappears and display remains black. If I attach HDMI display after boot is complete, I can see launcher application there. BTW, the same is happening with eglfs image.

I would appreciate any hints what might be wrong and how to debug/fix the problem.

Here is the build summary information and complete boot-log from serial console.

Regards,

Andrey.

[Olivier GALLIEN]

Hi @AndreyN​ 

Can you also share log when you plug / unplug HDMI cable please.

Olivier

[Olivier GALLIEN]

How do you power the board ? From PC or wall adaptor ?

Do you see red light ?

[AndreyN]

Hi @Community member​ 

Sorry for the slow response. I was out of office yesterday.

> Can you also share log when you plug / unplug HDMI cable please.

Connecting/disconnecting HDMI cable does not produce any logs in /var/log/messages or dmesg .

> How do you power the board ? From PC or wall adaptor ?

I am powering the board from active (powered) USB hub. The socket I am using is labeled USB3.0 2.4A. This HUB also shows 0.33A current usage when the board is connected.

> Do you see red light ?

In fact three of them =) . The LD6 close to the USER1 button, LD4 close to CN11 (I have USB cable connected to CN11) and another red one in the middle of the board under the screen near U7 chip.

Andrey.

[Olivier GALLIEN]

Hi @AndreyN​ 

LD6 ON means power source deliver not enough current for the platform.

This lead sometime to display problem. I noticed also in your log issue with Bluetooth.

Can you please manage to get a good power supply ?

Thx

Olivier

[AndreyN]

Hi @Community member​ 

I just tried USB wall adapter rated to 5V 2.1A output. LD6 is still ON (blinking couple of times at the beginning). Previously, there were USB camera, keyboard and mouse connected to the board. I've detached all of them, but it does not change anything. I can see bootloader splash-screen (so display seams to be ok) and during the boot it goes black. Sometimes I can see a noise on the screen (gray bars pattern with colored dots on them) but most of the time it remains just black.

Thanks,

Andrey.

[AndreyN]

Strange thing is that with provided SD-card DSI display works always. No problems at all despite LD6 is also ON.

So I am suspecting software related issue with image generated by recent Yocto image. But honestly, I have no idea how to debug the problem.

[Olivier GALLIEN]

Hi @AndreyN​ 

A 5V/3A typeC/typeC adapter is recommended to avoid any problem.

Olivier

[AndreyN]

@Community member​ , OK I will try to find more powerful adapter.

I am also curious whether clean build of the default weston image using recent Yocto SDK works on your site?

[Olivier GALLIEN]

Thanks for feedback.

So then could you please details software version that works and other don't work .. you build image by yourself right ?

Changing anything in configuration ?

Thx

Olivier