I just upgraded to Ubuntu 21.04 and now can no longer program my Arduino. Arduino uses a virtual serial port over USB. When I plug in my Arduino, a new serial port shows up (/dev/ttyACM0) and dmesg reports:
[61239.444141] usb 1-4: new full-speed USB device number 32 using xhci_hcd [61239.595108] usb 1-4: New USB device found, idVendor=2341, idProduct=0043, bcdDevice= 0.01 [61239.595123] usb 1-4: New USB device strings: Mfr=1, Product=2, SerialNumber=220 [61239.595130] usb 1-4: Manufacturer: Arduino (www.arduino.cc) [61239.595134] usb 1-4: SerialNumber: 75833353035351E011E0 [61239.598686] cdc_acm 1-4:1.0: ttyACM0: USB ACM device
So far this is the proper operation. However when I try to upload a new program to my Arduino I get the following error in the Arduino IDE:
avrdude: ser_open(): can't open device "/dev/ttyACM0": Input/output error
The only relevant line in /var/log/syslog seems to be:
kernel: [61936.113737] cdc_acm 1-4:1.0: acm_port_activate - usb_submit_urb(ctrl irq) failed
This worked fine before the upgrade to 21.04. A second computer also upgraded to 21.04 exhibits the same failure mode. A third computer running 20.10 with the same Arduino hardware and software works fine.
I am in the dialout group to have correct access permissions. As I said, this was working fine before the upgrade.
Any ideas, besides going back to 20.10?