On Fri, 11 Apr 2014 11:41:24 +0200 Johan Hovold <jhovold@xxxxxxxxx> wrote: > Fix characters being dropped by n_tty_write() due to a failure to > check the return value of tty_put_char() in do_output_char(). > > Characters are currently being dropped by write if a tty driver claims > to have write room available, but still fails to buffer any data Your driver is buggy. If you advertise a buffer you must honour it and neither shrink nor revoke it. For an URB based device you almost certainly want internal buffering so you can do proper packetisation. USB serial these days gets it right - see drivers/usb/serial/generic.c for a fairly simple kfifo based approach. Whether applying it to cdc_acm would make sense I don't know but it looks like it might be simpler over-all than the current arrangement. Alan -- 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
