| From 4473d054ceb572557954f9536731d39b20937b0c Mon Sep 17 00:00:00 2001 |
| From: Johan Hovold <johan@kernel.org> |
| Date: Wed, 5 Nov 2014 18:41:59 +0100 |
| Subject: USB: cdc-acm: only raise DTR on transitions from B0 |
| |
| From: Johan Hovold <johan@kernel.org> |
| |
| commit 4473d054ceb572557954f9536731d39b20937b0c upstream. |
| |
| Make sure to only raise DTR on transitions from B0 in set_termios. |
| |
| Also allow set_termios to be called from open with a termios_old of |
| NULL. Note that DTR will not be raised prematurely in this case. |
| |
| Signed-off-by: Johan Hovold <johan@kernel.org> |
| Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| |
| --- |
| drivers/usb/class/cdc-acm.c | 5 +++-- |
| 1 file changed, 3 insertions(+), 2 deletions(-) |
| |
| --- a/drivers/usb/class/cdc-acm.c |
| +++ b/drivers/usb/class/cdc-acm.c |
| @@ -980,11 +980,12 @@ static void acm_tty_set_termios(struct t |
| /* FIXME: Needs to clear unsupported bits in the termios */ |
| acm->clocal = ((termios->c_cflag & CLOCAL) != 0); |
| |
| - if (!newline.dwDTERate) { |
| + if (C_BAUD(tty) == B0) { |
| newline.dwDTERate = acm->line.dwDTERate; |
| newctrl &= ~ACM_CTRL_DTR; |
| - } else |
| + } else if (termios_old && (termios_old->c_cflag & CBAUD) == B0) { |
| newctrl |= ACM_CTRL_DTR; |
| + } |
| |
| if (newctrl != acm->ctrlout) |
| acm_set_control(acm, acm->ctrlout = newctrl); |
