Unable to run 08_video_dec_drm example

when running 08_video_dec_drm with --disable-video,
terminal outputs :

Set governor to performance before enabling profiler
Using VT number 3
[ERROR] (NvDrmRenderer.cpp:200) <renderer0> Couldn't open device: drm-nvdc
Error creating drm renderer
App run failed

after looking into NvDrmRenderer.cpp:200

 drm_fd = drmOpen(DRM_DEVICE_NAME, NULL);
  if (drm_fd == -1) {
    COMP_ERROR_MSG("Couldn't open device: " << DRM_DEVICE_NAME);
    goto error;
  }

so why open drm-nvdc failed?

before runnign thie demo, I’ve already ran the following command

nvstart-weston.sh
unset DISPLAY


and the /dev/dri/ folder has
by-path/ card0 renderD128

lsmod |grep “drm” gives:

nvidia_drm 61440 4
nvidia_modeset 1077248 2 nvidia_drm

desktop environment has already been disabled

Hi,
Do you disable default Ubuntu desktop? You would need to disable X11 before running the sample.

Hi,Dane.

We never disable the desktop on purpose, but when we reburn the kernel using the source code of L4T 34.1 from the download page, it seems desktop environment has already been disabled, and when we restart the device, we only see NVIDA logo, after logo showing up, no Ubuntu desktop environment comes out.

we also take [Jetson Linux API Reference: 08_video_dec_drm (Direct Rendering Manager) | NVIDIA Docs] as a reference.

Thanks for your help!

Hi,
We have confirmed this is an issue in 5.0.1 DP. We are debugging it. Will update.

Hi, Dane.

Any progress on this issue?

Hi,
We are working on it. It shall be fixed in next release.

Hi,
Any workaround at moment? We’re making a prototype that outputs result through HDMI without desktop environment.
But found no example as reference except DRM.

Is this an issue in 32.7.1 as well? The 08_video_dec_drm sample isn’t working on tx2 nx