staging: vt6655: Fix Warning on boot handle_irq_event_percpu.

commit 6cff1f6a upstream.

WARNING: CPU: 0 PID: 929 at /home/apw/COD/linux/kernel/irq/handle.c:147 handle_irq_event_percpu+0x1d1/0x1e0()
irq 17 handler device_intr+0x0/0xa80 [vt6655_stage] enabled interrupts

Using spin_lock_irqsave appears to fix this.
Signed-off-by: Malcolm Priestley <tvboxspy@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[bwh: Backported to 3.2: adjust context, indentation]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

drivers/staging/vt6655/device_main.c

@@ -2679,6 +2679,7 @@ static  irqreturn_t  device_intr(int irq,  void *dev_instance) {
     unsigned char byData = 0;
     int             ii= 0;
 //    unsigned char byRSSI;
+    unsigned long flags;
 
 
     MACvReadISR(pDevice->PortOffset, &pDevice->dwIsr);
@@ -2704,7 +2705,8 @@ static  irqreturn_t  device_intr(int irq,  void *dev_instance) {
 
     handled = 1;
     MACvIntDisable(pDevice->PortOffset);
-    spin_lock_irq(&pDevice->lock);
+
+    spin_lock_irqsave(&pDevice->lock, flags);
 
     //Make sure current page is 0
     VNSvInPortB(pDevice->PortOffset + MAC_REG_PAGE1SEL, &byOrgPageSel);
@@ -2952,7 +2954,8 @@ static  irqreturn_t  device_intr(int irq,  void *dev_instance) {
         MACvSelectPage1(pDevice->PortOffset);
     }
 
-    spin_unlock_irq(&pDevice->lock);
+    spin_unlock_irqrestore(&pDevice->lock, flags);
+
     MACvIntEnable(pDevice->PortOffset, IMR_MASK_VALUE);
 
     return IRQ_RETVAL(handled);