Canon EOS 550D - Parallel captures are sometimes slow and can break PTP

[mkstickx]

We have the following setup:

Host: Raspberry Pi 4 Cameras: 2 x Canon EOS 550D Version: gphoto2 2.5.27 ( installed via apt)

We run capture and download on both cameras in parallel, triggered via a bash script. This takes somewhere between 4 seconds and up to >60 seconds. I assume there is some general timing issue / conflict with the USB going on here? Sometimes this seems to result in one camera basically "breaking", as far as i understand the PTP seems to be permanently stuck at some point.

No gvfs processes are running.

I was able to capture the point where one of the cameras stopped working. I piped the debug logs of booth cameras into one file as I hoped this might help with tracing the timing (sorry if this is actually just confusing). I also included (separate) logs for running the same command on the cameras after one of them stopped working.

logs.zip

I would be grateful for any pointers that might help me avoid this bug. Thanks in advance.