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Hello,
Thank you for your detailed description and log snippet. I understand you’re experiencing issues with the etnaviv graphics driver on your Verdin iMX8M Plus WB (Wi-Fi/Bluetooth) 2GB variant, where /dev/dri/renderD128 does not appear, although framebuffer and basic Weston with software rendering does work. Meanwhile, the non-WB 4GB variant works as expected.
Let’s go through a checklist and some troubleshooting steps:
1. Hardware Differences (WB vs. non-WB)
The WB variant primarily differs by the addition of the Wi-Fi/Bluetooth module (AW-CM276NF) (Verdin iMX8M Plus module variants). Typically, the base GPU/NPU resources should be available on both, but sometimes pin multiplexing or shared resources or power domain init can introduce subtle changes.
2. PGC Power Domain Failures
The repeated log:
[ 5.174012] imx-pgc imx-pgc-domain.4: failed to command PGC
suggests a problem with the power gating controller (PGC) for a particular domain, possibly the GPU or a related subsystem.
3. Device Tree Consistency
You’ve tried with the original Dahlia device tree, which is good. Please ensure you are using the Device Tree Binary (.dtb) matching specifically your WB SOM variant. Sometimes, differences in pinmux or power domains for the WB variant may require a .dtb generated by specifying the correct part number.
4. Kernel/DTS Configuration
Ensure the GPU node is not disabled in your device tree and that it correctly matches your SOM variant. Look for status = "okay"; under the GPU nodes.
5. Firmware and U-Boot
The NPU probe defer (platform 38500000.npu: deferred probe pending) might be unrelated, but check that you’re using the reference firmware/U-Boot built for your WB module. Rare differences in non-volatile configuration or device tree overlays are possible.
6. Memory Differences
You have 2GB on the WB, 4GB on the non-WB variant. While this shouldn’t directly affect GPU/etnaviv initialization, some deeper issues could arise if reserved memory in the device tree is tuned for a 4GB SOM and then used with a 2GB module. Make sure any reserved memory regions (such as cma, gpu_reserved, or similar) in your .dts don’t exceed what is actually available.
7. Driver Probes and Kernel Logs
Check for etnaviv (or drm) specific errors earlier in your dmesg (search for “etnaviv”, “gpu”, “drm”, etc.). Sometimes the actual error message is earlier than the first failing log you posted.
8. Reference Images
If possible, try using a Toradex Reference Multimedia Image temporarily to check if the GPU brings up /dev/dri/renderD128 using the default Yocto/Torizon images. This can help determine if the issue is device tree, driver, or distribution specific.
9. Software Version
You mention a custom distro based on kernel 6.12.35-0. Toradex typically uses LTS kernel mainline backports and verified branches. Consider trying with the recommended kernel versions to rule out any kernel driver regression or compatibility issue.
10. Display Connection
Since /dev/dri/card1 is created and your display works, the display controller is likely OK. The absence of /dev/dri/renderD128 strongly suggests the GPU node did not finish initialization.
Suggested Initial Actions
- Double-check .dtb and overlays: make sure they match WB + Dahlia + your panel configuration.
- Search dmesg for “gpu”, “etnaviv”, “drm”, and post those lines here.
- If you have a serial console, enable maximum kernel debug for the etnaviv driver to get additional logs about why initialization failed.
- Compare the reserved memory regions in the device tree between both SOM variants.
- Try the reference images from Toradex as a baseline test if possible.
If you can post the output of:
grep -iE "etnaviv|galcore|gpu|drm" dmesg.log
and/or your device tree GPU section, I can assist you further.
Let me know if you need step-by-step help with any of the above or have more logs to share!
Best regards,
Toradex AI Assistant.
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