DietPi-Config | RPi: Add modern RPi camera module support

[isarrider]

Hi,

just as a hint for other users,
in my Octoprint as docker container setup,
the webcam only works, if I include
camera_auto_detect=1
in the config.txt on my Pi4

Maybe put it right above the
start_x=1

BR,
Alex

[MichaIng]

Many thanks for your report.

Indeed I recognised this. Basically start_x=1 is to enable the legacy firmware based camera features, when the legacy non-GL display driver or fake KMS is used. When full KMS is used camera_auto_detect=1 is the correct way to enable the camera module, making use of generic libcamera and V4L2 libraries, as far as I understand. start_x is then not required.

We can toggle the correct setting based on display driver:

• When enabling the camera module option, setting camera_auto_detect=1 or start_x=1 based on whether full KMS is used or not.
• When switching between fake KMS/full KMS/legacy and the camera module is enabled, switch between camera_auto_detect=1 and start_x=1 accordingly.

Just to be sure, can you verify that you have full KMS enabled?

grep 'vc4-.*-v3d' /boot/config.txt

[isarrider]

it seems my statement wasnt right afterall...
after a reboot - the cam only works with start_x=1,
I had to set #camera_auto_detect=1...
But now the picture also became messed up...

[isarrider]

Ill investigate further...
(also some peops think its related to bullseye: https://issueexplorer.com/issue/raspberrypi/linux/4697)

[isarrider]

ok, it seems my env variables didnt work out...
situation now is:
start_x=1
#camera_auto_detect=1
(and docker run -d --restart -v octoprint:/octoprint --device /dev/ttyUSB0:/dev/ttyUSB0 --device /dev/video0:/dev/video0 -e ENABLE_MJPG_STREAMER=true -e "MJPG_STREAMER_INPUT=-r 800x600 -f 15 -y" -p 80:80 --name octoprint octoprint/octoprint)
works now...
sry for the confusion...

[MichaIng]

Can you check with the suggested command whether KMS is enabled or not? As said, as far as I understood, camera_auto_detect=1 works only with full KMS enabled, while start_x=1 works only with legacy or fake KMS driver.

[isarrider]

grep 'vc4-.*-v3d' /boot/config.txt throw nth out...

[MichaIng]

Okay, then you do not have KMS enabled and it makes sense that start_x=1 must be used instead of camera_auto_detect=1. You could test to switch:

sed -i 's/^[[:blank:]]*start_x=.*$/#start_x=0/' /boot/config.txt
G_CONFIG_INJECT 'dtoverlay=vc4-f?kms-v3d' 'dtoverlay=vc4-kms-v3d' /boot/config.txt
G_CONFIG_INJECT 'camera_auto_detect=' 'camera_auto_detect=1' /boot/config.txt
reboot

[isarrider]

doesnt boot anymore after these 4 cmds...

[MichaIng]

?? Are you sure that it is not just the screen which stays blank for a while? It is basically impossible to break boot with those changes, even invalid entries are gracefully ignored. But when during boot it is switched from framebuffer output to KMS, the screen blanks for a while (some seconds). We also got reports where the monitor stood in energy savings mode for some reason. So check SSH.

[isarrider]

I am using it always per ssh...

[isarrider]

changed it back > boots

[MichaIng]

Mysterious, it is actually impossible that those commands have this effect, even with typos inside. Only if somehow KMS triggers a bit of additional power usage at some boot stage or so.

Ah, if I remember correctly in the one case where the screen stood blank, commenting the gpu_mem_* settings solved it, hence reducing GPU memory back to default. The KMS driver does not use this anymore but the system memory via CMA instead. Not sure how/why increased GPU memory causes this, as long as there is sufficient system memory, but probably it as well has a side effect in your case. Puhh, this makes our implementation more complicated as I'm not sure whether with KMS there is still a reason/use case where increased GPU memory may be needed 🤔.

[isarrider]

I have set it to 128MB (the GPU mem)
tmr I can do additional tests...

[MichaIng]

Jep, with start_x=1, 128 MiB is added automatically, also required to cover full legacy camera support, but the new implementation doesn't require it. Since I have no other explanation why the system wouldn't boot, when you find time, would be worth a test.

[isarrider]

ok, it seems it is somehow related with the Pi4 being powered by the 3D-Printer...
When I power it with an external Powerplug, it comes up...
Ill dig into it a bit more...

[isarrider]

Ok, it cannot load the webcam with dtoverlay=vc4-kms-v3d
Ill go back to my old "legacy" setup...

[isarrider]

https://forums.raspberrypi.com/viewtopic.php?p=1958297

[isarrider]

as info...

[isarrider]

Ill test on the weekend a bit more...

[isarrider]

https://forums.raspberrypi.com/viewtopic.php?t=319596