STM32MP157-EV1 Display not working on first boot

[pme991]

I'm trying to get STM32MP157F-EV1 board working with the STM32Cube ecosystem.  I have successfully followed the getting started guide., STM32MP157x-EV1 Lets Start   URL.  I get to the last step in  /Populate_the_target_and_boot_the_image, (Step 8), Boot the Board and GUI never shows up on Display.   After multiple reboots, reflashes, I thought let me go to next step, anyways, https://wiki.st.com/stm32mpu/wiki/Getting_started/STM32MP1_boards/STM32MP157x-EV1/Let%27s_start/Execute_basic_commands .  Well it turns out that I am able to login to device using Minicom.  I checked dmesg output, 

dmesg | grep display
[ 0.117034] platform 5a001000.display-controller: Fixed dependency cycle(s) with /soc/dsi@5a000000
[ 0.131004] platform 5a001000.display-controller: Fixed dependency cycle(s) with /soc/dsi@5a000000
[ 0.131240] platform 5a000000.dsi: Fixed dependency cycle(s) with /soc/display-controller@5a001000
[ 2.751026] stm32-display-dsi 5a000000.dsi: Fixed dependency cycle(s) with /soc/dsi@5a000000/panel-dsi@0
[ 2.863569] [drm] Initialized stm 1.0.0 20170330 for 5a001000.display-controller on minor 0
[ 19.592612] stm32-display-dsi 5a000000.dsi: Timeout during read operation
[ 35.242363] stm32-display-dsi 5a000000.dsi: Timeout during read operatio

I am wondering if I am doing a step incorrectly, but I just follwed the Guide.  So wondering if  a) Documentation is incorrect, or b) my HW display is bad.

Demo Launcher does not display.

Using, Create a simple Hello World program application I am able to compile "Hello World" program but it too, does not display a UI on STM32MP157F-ev1

Where else can I look for HW display not working or what additional information is needed to troubleshoot?

[Erwan SZYMANSKI]

Hello @pme991 ,
Can you attach the complete boot logs of your board, as well as a picture of your setup ?

Do you at least see a back-light on your screen or is it completely black without any sign of life ?

Kind regards,
Erwan.

[pme991]

@Erwan SZYMANSKI 

Let me know the location of the boot log you wish to view, I am happy to provide, I am attaching output from dmesg.  Here is picture of my board, all LED seems to be functioning.  Display is dark, I don't believe it is backlit.

[pme991]

@Erwan SZYMANSKI 

Some additional info, in dmesg output (dmesg.txt) I see this failure:

[ 2.915285] stmfx-core 0-0042: Boot chip failed: -6
[ 2.918782] ------------[ cut here ]------------
[ 2.920871] mmcblk1: p1 p2 p3 p4 p5 p6 p7 p8 p9 p10 p11
[ 2.923421] WARNING: CPU: 1 PID: 47 at drivers/regulator/core.c:2403 _regulator_put+0x15c/0x164
[ 2.937426] Modules linked in:
[ 2.940387] CPU: 1 PID: 47 Comm: kworker/u4:4 Not tainted 6.1.82 #1
[ 2.946658] Hardware name: STM32 (Device Tree Support)
[ 2.951816] Workqueue: events_unbound deferred_probe_work_func
[ 2.957608] unwind_backtrace from show_stack+0x10/0x14

Here is output file from "journalctl -xb" 

[Erwan SZYMANSKI]

Hello @pme991 ,
For sure there is a communication problem with your display, we can clearly see it thanks to following logs in  your dmesg.txt : 

[   19.192278] stm32-display-dsi 5a000000.dsi: Timeout during read operation
[   19.197685] panel-rocktech-hx8394 5a000000.dsi.0: could not read MTP ID1

As you say that you only took the Starter Package, I will check internally if we had a similar case in our test farm. If not, we can consider an HW issue with the DSI panel.

I will let you informed ASAP.

Kind regards,
Erwan.

[pme991 · Accepted solution]

@Erwan SZYMANSKI ,

This issue is resolved on my end.  Turns out one of the boards was  loose, and not set properly.  After I removed board (power goes into)  and reseated it on the board, the display work properly.

Thanks