Some typical issues related to the DRM/KMS framework are listed below. Solutions or debugging methods are proposed for these issues.
If your issue is not listed, try also looking in the articles in the DRM/KMS or troubleshooting grids categories.
| Symptom | Resolution |
|---|---|
Board $> ./myQtApplication Could not queue DRM page flip! (Permission denied) Could not queue DRM page flip! (Permission denied) |
The psplash-drm userland splash screen is running and is then the DRM master, avoiding other DRM applications to access to DRM/KMS. Please stop this psplash-drm application with the command below before running your use case: Board $> psplash-drm-quit Note: You may need to enter "export QT_QPA_EGLFS_ALWAYS_SET_MODE=1" before running your Qt application, please refer to the Qt documentation. |
Board $> echo 32 > /sys/class/backlight/5a000000.dsi.0/brightness sh: write error: No such device or address |
On this board, the panel backlight is related to a MIPI® DSI panel. This backlight can be modified only if the panel is already powered on. That is probably not the case here. |