The list below contains some typical issues related to the DRM/KMS framework. Solutions or debugging methods are proposed for these issues.
If your issue is not listed in the table below, try also looking in the articles available in the DRM/KMS or troubleshooting grids categories.
Symptom | Resolution |
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./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: psplash-drm-quit Note: You may need to enter "export QT_QPA_EGLFS_ALWAYS_SET_MODE=1" before running your Qt application. For further information, refer to the Qt documentation. |
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. |
I/TC: Resumed E/TC:0 tzc_it_handler:79 TZC permission failure E/TC:0 dump_fail_filter:417 Overrun violation on filter 0 E/TC:0 dump_fail_filter:420 Permission violation on filter 0 E/TC:0 dump_fail_filter:425 Violation @0xdce1ff80, non-secure unprivileged read, AXI ID 403 E/TC:0 Panic at core/arch/arm/plat-stm32mp1/plat_tzc400.c:84 <tzc_it_handler> E/TC:0 TEE load address @ 0xde000000 |
This trace indicates that the TZC internal peripheral is detecting a "permission violation" made by the master whose AXI ID is 0x403. It corresponds to the LTDC internal peripheral (LTDC NSAID=0b0011, please refer to the STM32 reference manuals for details).
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