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>

1 files changed, 7 insertions, 0 deletions

diff --git a/drivers/usb/serial/io_ti.c b/drivers/usb/serial/io_ti.c
index 63e044adc19a..39d71fdb5071 100644
--- a/drivers/usb/serial/io_ti.c
+++ b/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;
 }