[PATCH 3.16 172/370] USB: serial: quatech2: fix sleep-while-atomic in close

Ben Hutchings
2017-03-10T13:59:56Z

From: Johan Hovold <johan@kernel.org>

commit f09d1886a41e9063b43da493ef0e845ac8afd2fa upstream.

The write URB was being killed using the synchronous interface while
holding a spin lock in close().

Simply drop the lock and busy-flag update, something which would have
been taken care of by the completion handler if the URB was in flight.

Fixes: f7a33e608d9a ("USB: serial: add quatech2 usb to serial driver")
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
---
drivers/usb/serial/quatech2.c | 4 ----
1 file changed, 4 deletions(-)

--- a/drivers/usb/serial/quatech2.c
+++ b/drivers/usb/serial/quatech2.c
@@ -408,16 +408,12 @@ static void qt2_close(struct usb_serial_
{
struct usb_serial *serial;
struct qt2_port_private *port_priv;
- unsigned long flags;
int i;

serial = port->serial;
port_priv = usb_get_serial_port_data(port);

- spin_lock_irqsave(&port_priv->urb_lock, flags);
usb_kill_urb(port_priv->write_urb);
- port_priv->urb_in_use = false;
- spin_unlock_irqrestore(&port_priv->urb_lock, flags);

/* flush the port transmit buffer */
i = usb_control_msg(serial->dev,