From 08c7ad7ee0ea0243180e16b254b2921a22293bce Mon Sep 17 00:00:00 2001 From: Johan Hovold Date: Sun, 12 Sep 2010 16:31:45 +0200 Subject: [PATCH] USB: ftdi_sio: revert "USB: ftdi_sio: fix DTR/RTS line modes" This reverts commit 825a3309202b504b637d27c6beeb5a5e876b71d7. RTS and DTR should not be modified based on CRTSCTS when calling set_termios. Modem control lines are raised at port open by the tty layer and should stay raised regardless of whether hardware flow control is enabled or not. This is in conformance with the way serial ports work today and many applications depend on this behaviour to be able to talk to hardware implementing hardware flow control (without the applications actually using it). Hardware which expects different behaviour on these lines can always use TIOCMSET/TIOCMBI[SC] after port open to change them. Reported-by: Daniel Mack Reported-by: Dave Mielke Signed-off-by: Johan Hovold Cc: stable Signed-off-by: Greg Kroah-Hartman --- drivers/usb/serial/ftdi_sio.c | 4 ---- 1 file changed, 4 deletions(-) diff --git a/drivers/usb/serial/ftdi_sio.c b/drivers/usb/serial/ftdi_sio.c index 6e6b0da592878..42fea29637b32 100644 --- a/drivers/usb/serial/ftdi_sio.c +++ b/drivers/usb/serial/ftdi_sio.c @@ -2029,8 +2029,6 @@ static void ftdi_set_termios(struct tty_struct *tty, "urb failed to set to rts/cts flow control\n"); } - /* raise DTR/RTS */ - set_mctrl(port, TIOCM_DTR | TIOCM_RTS); } else { /* * Xon/Xoff code @@ -2078,8 +2076,6 @@ static void ftdi_set_termios(struct tty_struct *tty, } } - /* lower DTR/RTS */ - clear_mctrl(port, TIOCM_DTR | TIOCM_RTS); } return; } -- 2.39.5