On Wed, Apr 17, 2013 at 07:43:11PM +0200, Karsten Malcher wrote: > Am 17.04.2013 15:13, schrieb Johan Hovold: > > Can you minimise your test setup using a custom program which only opens > > the device, initialises it, writes the four characters (e.g. "test") > > and reads them back (over you hardwired loop) before closing the device > > again? > > I have used a little perl program that opens the port and send "Test" > to the looped back device. > The length of the log looks good. Great. Now I can see what's going on. The only problem (?) is that everything seems to be working. The write succeeds and the four bytes are read back as they should by the driver. The first thing that comes to mind that could prevent you from reading the received data would be if the tty device is configured for canonical input processing. Have you made sure this is not the case? Can you read the data back if you add a newline to your test string (e.g. "test\n")? > > Make sure to verify it using a working device first. > > I use this script with a ch341 adapter and it works. Hmmm. Did you remember to initialise the device (e.g. set the termios flags)? Johan -- 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
