atl1: add value to check ability of reenabling IRQs

Unfortunately it is not clear from code is usage of
IMR register possible or not. So, to prevent possible
side-effects of reading this register i prefer store
interrupts enable flag separately.
Signed-off-by: Tony Zelenoff <antonz@parallels.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/atheros/atlx/atl1.h

@@ -783,6 +783,12 @@ struct atl1_adapter {
 	u16 ict;		/* interrupt clear timer (2us resolution */
 	struct mii_if_info mii;	/* MII interface info */
 
+	/*
+	 * Use this value to check is napi handler allowed to
+	 * enable ints or not
+	 */
+	bool int_enabled;
+
 	u32 bd_number;		/* board number */
 	bool pci_using_64;
 	struct atl1_hw hw;

drivers/net/ethernet/atheros/atlx/atlx.c

@@ -169,6 +169,7 @@ static inline void atlx_imr_set(struct atlx_adapter *adapter,
 static void atlx_irq_enable(struct atlx_adapter *adapter)
 {
 	atlx_imr_set(adapter, IMR_NORMAL_MASK);
+	adapter->int_enabled = true;
 }
 
 /*
@@ -177,6 +178,7 @@ static void atlx_irq_enable(struct atlx_adapter *adapter)
  */
 static void atlx_irq_disable(struct atlx_adapter *adapter)
 {
+	adapter->int_enabled = false;
 	atlx_imr_set(adapter, 0);
 	synchronize_irq(adapter->pdev->irq);
 }