staging: vt6656: lock changes: RXvMngWorkItem.

Narrow atomic locks in RXvMngWorkItem.

We must lock the DequeueRCB and RXvFreeRCB so that
they are in sync.

vMgrRxManagePacket can nolonger be atomically called.

There is no need for an overall lock.
Signed-off-by: Malcolm Priestley <tvboxspy@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/vt6656/dpc.c

@@ -1363,34 +1363,43 @@ void RXvMngWorkItem(struct work_struct *work)
 	struct vnt_rcb *pRCB = NULL;
 	struct vnt_rx_mgmt *pRxPacket;
 	int bReAllocSkb = false;
+	unsigned long flags;
 
 	if (pDevice->Flags & fMP_DISCONNECTED)
 		return;
 
     DBG_PRT(MSG_LEVEL_DEBUG, KERN_INFO"---->Rx Mng Thread\n");
 
-    spin_lock_irq(&pDevice->lock);
     while (pDevice->NumRecvMngList!=0)
     {
+	spin_lock_irqsave(&pDevice->lock, flags);
+
         pRCB = pDevice->FirstRecvMngList;
         pDevice->NumRecvMngList--;
         DequeueRCB(pDevice->FirstRecvMngList, pDevice->LastRecvMngList);
+
+	spin_unlock_irqrestore(&pDevice->lock, flags);
+
         if(!pRCB){
             break;
         }
         pRxPacket = &(pRCB->sMngPacket);
 	vMgrRxManagePacket(pDevice, &pDevice->vnt_mgmt, pRxPacket);
         pRCB->Ref--;
-        if(pRCB->Ref == 0) {
-            DBG_PRT(MSG_LEVEL_DEBUG, KERN_INFO"RxvFreeMng %d %d\n",pDevice->NumRecvFreeList, pDevice->NumRecvMngList);
-            RXvFreeRCB(pRCB, bReAllocSkb);
-        } else {
+	if (pRCB->Ref == 0) {
+		DBG_PRT(MSG_LEVEL_DEBUG, KERN_INFO"RxvFreeMng %d %d\n",
+			pDevice->NumRecvFreeList, pDevice->NumRecvMngList);
+
+		spin_lock_irqsave(&pDevice->lock, flags);
+
+		RXvFreeRCB(pRCB, bReAllocSkb);
+
+		spin_unlock_irqrestore(&pDevice->lock, flags);
+	} else {
             DBG_PRT(MSG_LEVEL_DEBUG, KERN_INFO"Rx Mng Only we have the right to free RCB\n");
         }
     }
 
 	pDevice->bIsRxMngWorkItemQueued = false;
-	spin_unlock_irq(&pDevice->lock);
-
 }