I have compare the behavior against another serial dongle (pl2303). The behaviour is identical. 1) The Open function of the driver calls termios (given that the file is a tty). The termios function takes the serial setting (baudrate, #data bits, etc) from the tty, and sets the convertor adccordingly 2) ioctl(TCSETS) or ioctl(TCGETS) fails in the driver (what the tty layer is doing in between I however do not know). I no longer think there is issue. This sort of brings me back to the start of the thread: Using cat and echo I see buffering effects. Data written into a tty is not directly flush out on the receiving tty. If I for instance dump around 200 charactes, and then 10 characters via echo into the sending device, it is not necessarily directly dumped by "cat" hanging on the receiving device. Putting more characters into the sending device eventually flushes it out on the receiving terminal. I would like to write a test program that exchanges data between 2 serial ports. Using VTIME and VMIN, it should be possible to avoid buffering of the tty . My program does not really work. By now, I have read most of the serial- programing-guides. I guess I am not the first one to try this and wonder if there are test harenesses available that are known to work. 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
