6.x breaks low level USB commands?

[armbuilder]

Was using a 5.15.x version of Arabian on an orange pi 4, and upgraded to latest 6.7.x image seems to have broken low level usb (specifically USB to ACM devices). 

 

Used the following command to reset an STM32 device over USB (stm32 is connected directly to USB and shows up as a ttyACM0 device in linux)

python -c 'import termios; termios.tcsendbreak(3, 0)' 3>/dev/ttyACM0

this worked great but now no longer does. Any ideas?

 

Anyway we can test if its an updated driver issue by reverting to older  usb driver or possible a kernel issue?

 

Seems to be a Armbian specific issue, since ubuntu on amd64 system with 6.x kernel works fine as well