USB: io_ti: lock mcr and msr shadows properly

Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/usb/serial/io_ti.c

@@ -2559,9 +2559,11 @@ static int edge_tiocmset (struct usb_serial_port *port, struct file *file, unsig
 {
 	struct edgeport_port *edge_port = usb_get_serial_port_data(port);
 	unsigned int mcr;
+	unsigned long flags;
 
 	dbg("%s - port %d", __FUNCTION__, port->number);
 
+	spin_lock_irqsave(&edge_port->ep_lock, flags);
 	mcr = edge_port->shadow_mcr;
 	if (set & TIOCM_RTS)
 		mcr |= MCR_RTS;
@@ -2578,6 +2580,7 @@ static int edge_tiocmset (struct usb_serial_port *port, struct file *file, unsig
 		mcr &= ~MCR_LOOPBACK;
 
 	edge_port->shadow_mcr = mcr;
+	spin_unlock_irqrestore(&edge_port->ep_lock, flags);
 
 	TIRestoreMCR (edge_port, mcr);
 
@@ -2590,9 +2593,12 @@ static int edge_tiocmget(struct usb_serial_port *port, struct file *file)
 	unsigned int result = 0;
 	unsigned int msr;
 	unsigned int mcr;
+	unsigned long flags;
 
 	dbg("%s - port %d", __FUNCTION__, port->number);
 
+	spin_lock_irqsave(&edge_port->ep_lock, flags);
+
 	msr = edge_port->shadow_msr;
 	mcr = edge_port->shadow_mcr;
 	result = ((mcr & MCR_DTR)	? TIOCM_DTR: 0)	  /* 0x002 */
@@ -2604,6 +2610,7 @@ static int edge_tiocmget(struct usb_serial_port *port, struct file *file)
 
 
 	dbg("%s -- %x", __FUNCTION__, result);
+	spin_unlock_irqrestore(&edge_port->ep_lock, flags);
 
 	return result;
 }