Repeated open/clode of ACM cause crash

[Gregwar]

Hi,

If I simply use this code :

    if (SerialUSB.available()) {
        SerialUSB.write(SerialUSB.read());
    }

And I write a python script that just open the port, write some "a" and read the "a"s, if I run this python script many times this cause the crash of the ACM port:

serial.serialutil.SerialException: could not open port /dev/ttyACM0: [Errno 5] Input/output error: '/dev/ttyACM0'

I have the same issue in many cases like this and I don't know exactly what's going on, my computer says :

Mar 27 16:01:38 bob kernel: [17103.998984] xhci_hcd 0000:03:00.0: ERROR no room on ep ring
Mar 27 16:01:38 bob kernel: [17103.998992] cdc_acm 2-1:1.0: acm_tty_open - usb_submit_urb(ctrl irq) failed
Mar 27 16:01:38 bob kernel: [17103.998997] tty_port_close_start: tty->count = 1 port count = 0.

Any idea ?

[poslathian]

why was this closed? any new information?

[Gregwar]

Hi,

I figured out that the cdc_acm driver of my computer was the problem since I could not reproduce the bug under other computers

My computer is on Ubuntu 12.04 while the other ones are Debian and works