CM3+ with LT070ME0500 DSI display

Hello Guys,

I would like to support you with testing on a custom hardware.

I have my own designed hardware basing on CM3+ and LT070ME05000 DSI display and of course a lot of additional perpherals.

Now the system already works close to fine using Raspberry OS with the latest firmware. (kernel 5.10.46).

Today, I have dowloaded the latest nightly build from here (LibreELEC-RPi2.arm-10.0-nightly-20210628-f904c2e.img.gz).

Added the same lines in my config.txt:

ignore_lcd=1

dtoverlay=vc4-kms-v3d

dtoverlay=vc4-kms-dsi-lt070me05000,reset=39,enable=38,dcdc-en=41

Unfortunately, my LCD remains dark wathever I do, although I have tried many parameter changes.

Using HDMI everythig works fine, but the final target would be this huge LCD screen.

Please let me help to give life to this screen with your nice LibreELEC.

In hardware staff I have a lot of experiences as an electrical development engineer, but to be honest, for Linux, KODI, LE, RPi software staff I am really newbie.

dmesg says this:

[ 3.167778] [drm:vc4_dsi_bind] *ERROR* Failed to get DMA channel: -19

[ 3.167819] vc4-drm soc:gpu: failed to bind 3f700000.dsi (ops 0x80c5eb40): -19

Which is from here: "ret = PTR_ERR(dsi->reg_dma_chan);" from "vc4_dsi.c" line 1514.

So please handle me as a 5-year-old kid

Thanks for your great help and keep on!

Quote from HiassofT

Please test with the latest nightly (currently 20210704). If that doesn't work please provide a full "pastekodi" log - ssh in, run "pastekodi" and post the URL

so long,

Hias

Thanks for your quick response HiassofT.

Here is the link from pastekodi: LINK

Quote from Da Flex

You're still at log level 0, so we are missing some info. Activate debug logging at GUI (HUD will appear), and do it again.

PS: Reboot before running pastekodi.

OK, so I commented out "dtoverlay=vc4-kms-dsi-lt070me05000,reset=39,enable=38,dcdc-en=41" in config.txt to be able to log in using HDMI.

Then log level set for debug >>> HUD appeared >>> power off >>> revert config.txt changes >>> power up >>> log in SSH >>> run pastekodi

Here are the results: LINK

Thanks Da Flex, HiassofT.

Quote from Da Flex

Thanks!

Code

Jul 05 18:40:00.805362 LibreELEC systemd[1]: Condition check resulted in Kodi user autostart script being skipped.

Please post the content of your autostart.sh.

"/storage/.config/autostart.sh" file does not exist.

Thanks guys,

Good to hear that you found my issue this quickly.

Please also help with the Goodix GT911 touchscreen attached.

CONFIG_TOUCHSCREEN_GOODIX

Should I use the procedure to add modules as it is readable on RPi website or is it different for LE?

Quote from HiassofT

deltasjimmy can you test if the display is working on RPi OS with the latest rpi-update kernel (currently 5.10.46-v7+)?

I built an LE image with the missing drivers included, but it just locks up on my RPi3B+ when I add the vc4-kms-dsi-lt070me05000 dtoverlay - and the same happens on RPiOS with latest kernel as well. I don't have any DSI displays here so not sure if that's the cause - the DSI driver is still under heavy development so it could be an issue in latest kernel, too.

so long,

Hias

Hi HiassofT,

As you can read my first post, the display already tested out with the latest RPi OS (kernel 5.10.46-v7+) using these additions in the config.txt:

ignore_lcd=1

dtoverlay=vc4-kms-v3d

dtoverlay=vc4-kms-dsi-lt070me05000,reset=39,enable=38,dcdc-en=41

This way the display works fine.

LibreELEC:

Yesterday, I have also compiled the latest nightly build with the next modifications in the "http://LibreELEC.tv/projects/RPi/devices/RPi2/linux/linux.arm.conf":

CONFIG_TOUCHSCREEN_GOODIX=m

CONFIG_DRM_PANEL_JDI_LT070ME05000=m

(I don't know if anything else is needed or not, please let me know if something more are required)

This way I have the same experiences as you have, the board does not boot, no logs within KODI or LE files.

For me , it means that the kernel can handle the display, so the problem is within KODI or LE.

To help you to figure out the problem, maybe I should activate the kernel UART debug feature then using a FTDI-FT232 cable I can log everything using my notebook.

If it helps then please let me know how can I activate this feature.

Here can see two photos of the board if interested.

Thanks for your great support, please keep on.

Good point HiassofT.

Suggested changes are made then image is re-compiled.

Then I could reproduce the behaviour.

1) When the board starts up with HDMI connected then the board boots up with LE GUI on the HDMI display.

2) When the board starts up with no HDMI connected then the LCD remains dark.

3) When HDMI is connected and the board is powered; after like 4-5 seconds the HDMI cable is removed then the board starts with LE GUI on the LCD.

So it looks that you and RPi devs can solve this issue next week. Good to hear

The next question is, how can I rotate the screen?

By the way the touch screen also works, but that one is oriented right.

(touchscreen-inverted-x and touchscreen-swapped-x-y in it's dtoverlay.)

Thanks guys this great job.

I have tried this line with different parameters today in cmdline.txt:

1) video=DSI-1:1200x1920@60,panel_orientation=left_side_up >>> nothing rotated

2) video=DSI-1:1200x1920@60,panel_orientation=right_side_up >>> nothing rotated

Then just for playing around:

3) video=DSI-1:1200x1920@60,panel_orientation=upside_down >>> LE logo is upside down, but GUI reversed back to original orientation

4) video=DSI-1:1200x1920@60,reflect_x=y >>> LE logo is mirrored on x axis, but GUI reversed back to original orientation

5) video=DSI-1:1200x1920@60,rotate=270 >>> nothing rotated

Also tried to use 'lcd_rotate' and'display_rotate' additionally in config.txt but nothing help.

It sounds that this won't be solved soon.

Does anybody work on this feature or is it planned from kodi side?