Hi,
Problem
I have an Apalis i.MX8 board with a 4K monitor. I am trying to make DMABuf be assigned to DRM plane in Weston.
It succeeds if the buffer is completely inside a half of screen (left or right).
If the buffer is at middle of screen, buffer cannot be assigned to DRM plane.
Please see the picture below.
Above is result when display DMABufs on 4K (3840x2160) monitor:
- 2 buffers are completely in the left half of screen (half screen width = 1920): The plane assignment is OKAY.
- 1 buffer is at middle of screen: The middle buffer cannot be assigned to DRM plane.
- 2 buffers are in left half and right half of screen, none at middle: The plane assignment is OKAY.
This problem doesn't happen if only one buffer is displayed.
How to reproduce
In my case, I implemented an application to create and display DMABuf, but the problem can be reproduced with `weston-simple-dmabuf-egl -g`.
1. Run `weston-simple-dmabuf-egl -g -s 1922`. Set size to 1922 to make sure output buffer will be middle of screen.
When only display one DMABuf, as we can see in `weston-debug` log, the plane assignment is okay.
Layer 5 (pos 0x50000000):
View 0 (role xdg_toplevel, PID 1138, surface ID 3, top-level window 'simple-dmabuf-egl', 0xaaaac18d7440):
position: (1079, 3) -> (3001, 1925) #### middle DMABuf
[fully opaque]
outputs: 0 (HDMI-A-1) (primary)
dmabuf buffer
format: 0x34325258 XRGB8888
modifier: 0x0
...
[atomic] drmModeAtomicCommit
[repaint] Using mixed state composition
[repaint] view 0xaaaac18d7440 on Overlay plane 39 #### DMABuf was assigned
2. Run another `weston-simple-dmabuf-egl -g -s 200`.
After add another DMABuf, the middle DMABuf failed to be assigned to plane with error "kernel test failed".
Layer 5 (pos 0x50000000):
View 0 (role xdg_toplevel, PID 1144, surface ID 3, top-level window 'simple-dmabuf-egl', 0xaaaac18bb190):
position: (2586, 1052) -> (2786, 1252) #### right DMABuf
[fully opaque]
outputs: 0 (HDMI-A-1) (primary)
dmabuf buffer
format: 0x34325258 XRGB8888
modifier: 0x0
View 1 (role xdg_toplevel, PID 1138, surface ID 3, top-level window 'simple-dmabuf-egl', 0xaaaac18d7440):
position: (1079, 3) -> (3001, 1925) #### middle DMABuf
[fully opaque]
outputs: 0 (HDMI-A-1) (primary)
dmabuf buffer
format: 0x34325258 XRGB8888
modifier: 0x0
...
[atomic] drmModeAtomicCommit
[overlay] provisionally placing view 0xaaaac18bb190 on overlay 39 in mixed mode #### right DMABuf
[view] view 0xaaaac18bb190 has been placed to overlay plane with computed zpos 3
...
[atomic] drmModeAtomicCommit
[overlay] not placing view 0xaaaac18d7440 on overlay 46 in mixed mode: kernel test failed
...
[atomic] drmModeAtomicCommit
[overlay] not placing view 0xaaaac18d7440 on overlay 53 in mixed mode: kernel test failed
...
[atomic] drmModeAtomicCommit
[repaint] Using mixed state composition
[repaint] view 0xaaaac18bb190 on Overlay plane 39 #### right DMABuf
[repaint] view 0xaaaac18d7440 using renderer composition #### middle DMABuf
Environment
- Board: Apalis i.MX8 QM
- Kernel: 5.4.193
- Weston: lf-5.10.y-1.0.0
- Monitor: 3840x2160
Weston configuration:
[core]
use-g2d=0
idle-time=0
Have you experienced this problem before or have any ideas about the cause of this issue?
Thank you very much,
Trung
