mainline camera drivers: system sometimes freezes when starting streaming

With the mainline camera drivers, currently https://source.puri.sm/Librem5/linux-next/-/merge_requests/430 running with byzantium on Evergreen, my system freezes after starting to stream via v4l2-ctl, see the script in the above MR. This happens every 3-4 reboots. When is works, it always works until I reboot. Then there's a chance of it to freeze again.

It happens with runtime PM disabled too.

trace-cmd doesn't save to a file properly in the failing case.

buffers seem to not being queued somehow: failing case:

        [  134.434528] videobuf2_common: vb2_core_streamon: start               
        [  134.619289] videobuf2_common: vb2_core_streamon: done ok             
        [  134.624689] vb2_ioctl_dqbuf: start                                   
        [  134.628183] vb2_dqbuf: start                

success case:

 [  148.532001] videobuf2_common: vb2_core_streamon: start               
        [  148.866438] videobuf2_common: vb2_core_streamon: done ok             
        [  148.871838] vb2_ioctl_dqbuf: start                                   
        [  148.875310] vb2_dqbuf: start                                         
        [  148.891619] vb2_ioctl_qbuf: start                                    
        [  148.894965] vb2_qbuf: start                                          
        [  148.897846] vb2_ioctl_dqbuf: start                                   
        [  148.901283] vb2_dqbuf: start                                         
        (and so on while streaming...)