Hello the userspace function tcgetattr, and tcsetattr result in calls to the ioctl-function of the corresponding driver. The command arguments are TCGETS, and TCSETS. None of the serial driver of the USB-subsystem however seem to implement TCGETS, or TCSETS. Are tcgetattr, and tcsetattr obsolete ? What function does a userspace program use to set serial device parameter like baudrate,etc. ? Thanks Tilman -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html