CDC-ACM locks up when closing terminal on host
Steps to reproduce:
- Reset card10 (firmware @ 3ccec228)
- Open debugger terminal (
picocom -b 115200 /dev/ttyACM0
) - Open CDC-ACM terminal (
picocom -b 115200 /dev/ttyACM1
) - Close CDC-ACM terminal (Press
^A^Q
) - Paste a long text into debugger terminal
Observation:
The debugger terminal becomes unresponsive. Under the hood, Epicardium is spinning in MAXUSB's acm_write
because its internal FIFO-buffer (129 bytes) if full and not emptied by the host.