Cannot change baud rate on usb serial device

view full story

http://unix.stackexchange.com – I recently upgraded to ubuntu 12.04 from 10.04. Under 10.04 I had no trouble using usbserial driver to connect to a device through the serial port. After the upgrade usually I cannot reset the baud rate: it is initialized to 9600, but my device needs 115200. When I try to reset the speed I get: $ sudo stty -F /dev/ttyUSB0 speed 9600 baud; line = 0; -brkint -imaxbel $ sudo stty -F /dev/ttyUSB0 115200 stty: /dev/ttyUSB0: unable to perform all requested operations $ sudo setserial -av /dev/ttyUSB0 Cannot get serial info: Invalid argument $ ls -l /dev/ttyUS* crw-rw---- 1 root dialout 188, 0 Nov (HowTos)