Duo 256MB - camera-test.sh kernel panic under low light conditions

Hello all!

Sorry for recreating the topic, I didn’t realize I could edit the topic title.

I noticed a very strange pattern (to me) with the kernel panics and the camera on the Duo 256 MB. So, I tried the camera sample again this morning and it was miraculously working! I was playing with the RTSP stream for a short while, but the moment I set the camera down the Duo kernel panicked. I thought that it might be due to a poor connection to the camera so I reconnected everything. I started camera-test.sh while holding the camera again and it was working again. Wiggled the cables, etc. Seemed fine.

I then waved at the camera and boom - kernel panic. I’ve been playing with it a bit more and then realize that if i start the same with the camera in a well lit scene, and then slowly block the light coming into the camera, it will panic when the scene starts to get dark.

I modified the sample_vi_fd example to remove both the NPU usage and the RTSP stream - essentially just captures frames from the camera. The crash/panic still happens even when the video encoder and NPU are not being fed data. They always come from random parts of the kernel and from garbage instruction pointers, which would suggest to me that whatever is going wrong is corrupting kernel memory.

Could this be some kind of ISP bug related to auto-exposure / auto-focus? Are there any userspace/TDL SDK options I can tweak to reduce this behavior?


I can not provide answer, sorry. Rather I want to ask whether have you been using a precompiled kernel objects and SDK in your experiments with camera ?

Yes, this is with the stock image. Downloaded the milkv-duo256m-v1.1.0-2024-0410.img.zip image from Releases · milkv-duo/duo-buildroot-sdk · GitHub, wrote it to an SD card, booted my Duo 256 MB attached to USB, ssh’d in, and ran camera-test.sh.

Per another thread (on github, i think), I built the latest git version of the samples (GitHub - milkv-duo/cvitek-tdl-sdk-sg200x). I get the same result with the latest git version of the samples as I do with the samples bundled in the image.

I then started disabling random parts of the sample to see if the crashes would go away, but even when it’s just fetching frames from the camera, the crashes still happen. I want to stress that in my experiments, I’ve not modified the image, kernel, or kernel objects in any way. Just copied over a new sample_vi_fd binary from the git version of the samples.

The steps to reproduce are hold the camera pointed at a reasonably well lit room, start camera-test.sh, then cover the lens with your hand. It’ll then panic. Doesn’t matter if it ran for a few minutes pointed at good light, the moment you cover the lens, it crashes.