diff --git a/drivers/usb/serial/ftdi_sio.c b/drivers/usb/serial/ftdi_sio.c index 8fe034d2d3e7..bd4298bb6750 100644 --- a/drivers/usb/serial/ftdi_sio.c +++ b/drivers/usb/serial/ftdi_sio.c @@ -2104,13 +2104,19 @@ static void ftdi_set_termios(struct tty_struct *tty, cflag = termios->c_cflag; - /* FIXME -For this cut I don't care if the line is really changing or - not - so just do the change regardless - should be able to - compare old_termios and tty->termios */ + if (old_termios->c_cflag == termios->c_cflag + && old_termios->c_ispeed == termios->c_ispeed + && old_termios->c_ospeed == termios->c_ospeed) + goto no_c_cflag_changes; + /* NOTE These routines can get interrupted by ftdi_sio_read_bulk_callback - need to examine what this means - don't see any problems yet */ + if ((old_termios->c_cflag & (CSIZE|PARODD|PARENB|CMSPAR|CSTOPB)) == + (termios->c_cflag & (CSIZE|PARODD|PARENB|CMSPAR|CSTOPB))) + goto no_data_parity_stop_changes; + /* Set number of data bits, parity, stop bits */ urb_value = 0; @@ -2151,6 +2157,7 @@ static void ftdi_set_termios(struct tty_struct *tty, } /* Now do the baudrate */ +no_data_parity_stop_changes: if ((cflag & CBAUD) == B0) { /* Disable flow control */ if (usb_control_msg(dev, usb_sndctrlpipe(dev, 0), @@ -2178,6 +2185,7 @@ static void ftdi_set_termios(struct tty_struct *tty, /* Set flow control */ /* Note device also supports DTR/CD (ugh) and Xon/Xoff in hardware */ +no_c_cflag_changes: if (cflag & CRTSCTS) { dbg("%s Setting to CRTSCTS flow control", __func__); if (usb_control_msg(dev,