Issue with /dev/dri/ with no desktop running

[oxoocoffee]

Creating a bug report/issue

• [x ] I have searched the existing open and closed issues

Required Information

• DietPi version |

G_DIETPI_VERSION_CORE=9
G_DIETPI_VERSION_SUB=3
G_DIETPI_VERSION_RC=0
G_GITBRANCH='master'
G_GITOWNER='MichaIng'

• Distro version | bookworm 0
• Kernel version | Linux DietPi 6.6.20+rpt-rpi-2712 #1 SMP PREEMPT Debian 1:6.6.20-1+rpt1 (2024-03-07) aarch64 GNU/Linux
• SBC model | RPi 5 Model B (aarch64) or (EG: RPi3)
• Firmware/EEPROM |

BOOTLOADER: up to date
   CURRENT: Sat Apr 20 10:53:30 UTC 2024 (1713610410)
    LATEST: Sat Apr 20 10:53:30 UTC 2024 (1713610410)
   RELEASE: default (/lib/firmware/raspberrypi/bootloader-2712/default)
            Use raspi-config to change the release.

• Power supply used | 200W multi-port USB charger
• SD card used | SanDisk 64G

Additional Information (if applicable)

• Software title | Discovered DRI when researching ticket #7029
• Was the software title installed freshly or updated/migrated? My test program which fais
• Can this issue be replicated on a fresh installation of DietPi? Yes

• Bug report ID | echo $G_HW_UUID

Steps to reproduce

1. Boot from a fresh image on rPi 5 and complete installation with our desktop selected.
2. Install build tools sudo apt install build-essential git cmake pkg-config libdrm-dev drm_info
3. ls /dev/dri/

drwxr-xr-x 2 root root        100 Apr 22 16:33 by-path
crw-rw---- 1 root video  226,   0 Apr 22 16:33 card0
crw-rw---- 1 root video  226,   1 Apr 22 16:33 card1
crw-rw---- 1 root render 226, 128 Apr 22 16:33 renderD128

4. Uncompress dri-test.tgz

5. cd dri-test/build && cmake .. && make

Expected behaviour

• See a full screen with a test chess checker. I do not know if it fully work since DRI initialization fails.

Actual behaviour

• Since my program terminates on a second call after open which is device.resources = drmModeGetResources(device.fd) with and error Failed to get DRM resources. Operation not supported

Extra details

• groups produced tty dialout sudo audio video users input render netdev gpio i2c spi

[MichaIng]

KMS is enabled, right?

grep dtoverlay=vc4-kms-v3d /boot/config.txt

Did you start the test program from within a desktop session? I don't know what it is doing, where "device" and "fd" (file descriptor?) are coming from, but maybe it requires a context or input to know which of the 2 DRI devices it should use?

Did you test this with RPi OS Bookworm?

[oxoocoffee]

@MichaIng

Yes. All tests were performed with dtoverlay=vc4-kms-v3d

• I did not stop from within a desktop. I have no desktop installed/running
• I did not test rPI OS. I can try to download it and see. What specific version do you suggest?

[oxoocoffee]

While looking into this issue some more today I found this #5049

Change the config.txt file to dtoverlay=vc4-kms-v3d-pi4