RPI Backlight overlay loaded without 7" Rapsberry Display

[pkdick]

Hello,

I have installed a Waveshare 7.9" DSI display in my MOODE setup. When I look at the boot messages with the dmesg command, I notice that the RPI Backlight overlay is loaded: when I try to quote the overlay in the config.txt, I also notice that my modification is cancelled each time I reboot.

This problem is not critical, but is there a way to work it out ?

Thank you in advance,
   

[Tim Curtis]

That was fixed way back in 9.0.5
- FIX: Boot config.txt dtoverlay=rpi-backlight causing journal log errors

For releases 9.0.5 and higher its a managed setting

Here's what that section of the shipped config.txt looks like

Code:

# Do not alter this section
# Integrated adapters
#dtoverlay=disable-bt
#dtoverlay=disable-wifi
# Audio overlays
#dtoverlay=none
#dtoverlay=force_eeprom_read=0
# PCI Express
#dtparam=pciex1
#dtparam=pciex1_gen=3
# Pi Touch
#dtoverlay=rpi-backlight
#dtoverlay=vc4-kms-dsi-7inch,invx,invy

[pkdick]

Hello Tim,

Thank you for your answer: I am currently running Moode 9.1.2 and each time I deactivate the rpi-backlight overlay in the config.txt, I found it reactivated after a reboot...  By the way, I never activated the overlay by myself.

   

[Tim Curtis]

Hello Tim,

Thank you for your answer: I am currently running Moode 9.1.2 and each time I deactivate the rpi-backlight overlay in the config.txt, I found it reactivated after a reboot...  By the way, I never activated the overlay by myself.

As I mentioned earlier Its a managed setting and any manual modifications will be overwritten during moode startup. The overlay is automatically enabled (uncommented) when the local display is started and commented out (#) when the local display is turned off.

To allow control over the individual setting "rpi-backlight" a new option would need to be added to Peripheral Config. I can add to the TODO list to investigate.

Is the setting only needed for the Pi 7" Touch?

[pkdick]

Hello Tim,

Thank you for this explanation which makes things clearer to me: as I do not own a 7" Pi Touch, I do not see the use to activate this overlay automatically, but as I said in my first message, it is not critical (it is just that I noticed the error messages in the dmesg log).

By the way, the Waveshare 7.9" DSI Display that I installed can be adjusted from the brightness point of view (https://www.waveshare.com/wiki/7.9inch_DSI_LCD): I wrote the command line "echo 100 | sudo tee /sys/class/backlight/*/brightness" in the rc.local file, so it is applied at each moode start.

Best regards,