[PATCH 4.4 15/38] USB: cdc-acm: fix TIOCMIWAIT

[Greg Kroah-Hartman <gregkh@linuxfoundation.org>]

4.4-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Johan Hovold <johan@kernel.org>

commit 18266403f3fe507f0246faa1d5432333a2f139ca upstream.

The TIOCMIWAIT implementation would return -EINVAL if any of the three
supported signals were included in the mask.

Instead of returning an error in case TIOCM_CTS is included, simply
drop the mask check completely, which is in accordance with how other
drivers implement this ioctl.

Fixes: 5a6a62bdb925 ("cdc-acm: add TIOCMIWAIT")
Signed-off-by: Johan Hovold <johan@kernel.org>
Acked-by: Oliver Neukum <oneukum@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 drivers/usb/class/cdc-acm.c |    2 --
 1 file changed, 2 deletions(-)

--- a/drivers/usb/class/cdc-acm.c
+++ b/drivers/usb/class/cdc-acm.c
@@ -877,8 +877,6 @@ static int wait_serial_change(struct acm
 	DECLARE_WAITQUEUE(wait, current);
 	struct async_icount old, new;
 
-	if (arg & (TIOCM_DSR | TIOCM_RI | TIOCM_CD ))
-		return -EINVAL;
 	do {
 		spin_lock_irq(&acm->read_lock);
 		old = acm->oldcount;