Diagonal Artifacts on MIPI-DSI Display When Running Weston on Torizon 6.8.x

Technical Support
, , ,
2

Hi, I’m the Toradex AI Assistant.

I might make mistakes or occasionally get you wrong. Our support team will step in if needed.

MIPI-DSI Display Issues with Weston on Torizon OS

The diagonal bands/stripes you’re experiencing when Weston starts on Torizon OS 6.8.x, while the splash screen displays correctly, suggest a display timing or configuration mismatch between the kernel framebuffer and Weston’s display handling.

Key Differences Between Splash Screen and Weston

The splash screen uses the kernel’s framebuffer directly, while Weston uses the DRM (Direct Rendering Manager) subsystem (1). This explains why the splash screen appears correctly but Weston shows distortions.

Troubleshooting Steps

1. Verify Display Configuration

Check if your display is properly recognized by examining the DRM interface:

# ls /sys/class/drm/*/status

(1)

You should see your DSI display listed. For MIPI-DSI displays, you’ll typically see something like:

/sys/class/drm/card0-DSI-1/status

(1)

2. Weston Configuration Issues

Your weston.ini configuration shows:

[output]
name=DSI-1
transform=rotate-90

The name value should match what weston-info reports from inside the running Weston container (1). You can verify this by running:

docker exec <weston-container> weston-info

(1)

3. Display Timing Verification

The timing parameters in your display driver may not be correctly interpreted by Weston. Based on the community discussions, similar issues have been resolved by ensuring proper clock configuration (2) (3).

4. Container Configuration

For Verdin iMX8M Mini, ensure you’re using the correct Weston container. Your Dockerfile references weston-vivante, which is appropriate for iMX8 platforms (4):

# docker container run -d --name=weston --net=host \
    --cap-add CAP_SYS_TTY_CONFIG \
   -v /dev:/dev -v /tmp:/tmp -v /run/udev/:/run/udev/ \
    --device-cgroup-rule="c 4:* rmw" --device-cgroup-rule="c 253:* rmw" \
    --device-cgroup-rule="c 13:* rmw" --device-cgroup-rule="c 226:* rmw" \
    --device-cgroup-rule="c 10:223 rmw" --device-cgroup-rule="c 199:0 rmw" \
    torizon/weston-imx8:4 \
    --developer

(4)

Potential Solutions

1. Try Software Rendering

Test if the issue is related to hardware acceleration by using software rendering:

Add --use-pixman to your Weston startup command (1).

2. Check Display Mode Settings

Your display flags show:

.flags = DRM_MODE_FLAG_NHSYNC | DRM_MODE_FLAG_NHSYNC

This appears to have a typo - you likely meant:

.flags = DRM_MODE_FLAG_NHSYNC | DRM_MODE_FLAG_NVSYNC

3. Verify Panel Driver Integration

Ensure your custom panel driver (tdo,ET055wu01) is properly loaded and recognized by the system. Check dmesg output for any panel-related errors.

Next Steps

  1. Verify the exact output name using weston-info
  2. Check dmesg logs for any DRM or display-related errors
  3. Test with --use-pixman to isolate hardware acceleration issues
  4. Ensure your device tree overlay is correctly applied in Torizon OS

The fact that your setup works with tdx-reference-multimedia-image but not with Torizon OS suggests there may be differences in the kernel configuration or display subsystem between the two environments.

Best regards, Toradex AI Assistant.

Did you like my answer? :+1: :-1:

If I answered your question, please tick the “Solution” checkbox.

For follow-up questions to me, please use @ToradexAI in your post.