e1000e: remove irq_sem

irq_sem can safely be removed by auditing all irq.*able sites to
make sure that interrupts don't get enabled unexpectedly when the
interface is down.
Signed-off-by: NJesse Brandeburg <jesse.brandeburg@intel.com>
Signed-off-by: NAuke Kok <auke-jan.h.kok@intel.com>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

drivers/net/e1000e/e1000.h

@@ -167,9 +167,6 @@ struct e1000_adapter {
 
 	spinlock_t tx_queue_lock; /* prevent concurrent tail updates */
 
-	/* this is still needed for 82571 and above */
-	atomic_t irq_sem;
-
 	/* track device up/down/testing state */
 	unsigned long state;
 

drivers/net/e1000e/netdev.c

@@ -836,9 +836,7 @@ static irqreturn_t e1000_intr_msi(int irq, void *data)
 	struct e1000_hw *hw = &adapter->hw;
 	u32 icr = er32(ICR);
 
-	/* read ICR disables interrupts using IAM, so keep up with our
-	 * enable/disable accounting */
-	atomic_inc(&adapter->irq_sem);
+	/* read ICR disables interrupts using IAM */
 
 	if (icr & (E1000_ICR_RXSEQ | E1000_ICR_LSC)) {
 		hw->mac.get_link_status = 1;
@@ -868,8 +866,6 @@ static irqreturn_t e1000_intr_msi(int irq, void *data)
 		adapter->total_rx_bytes = 0;
 		adapter->total_rx_packets = 0;
 		__netif_rx_schedule(netdev, &adapter->napi);
-	} else {
-		atomic_dec(&adapter->irq_sem);
 	}
 
 	return IRQ_HANDLED;
@@ -895,11 +891,8 @@ static irqreturn_t e1000_intr(int irq, void *data)
 	if (!(icr & E1000_ICR_INT_ASSERTED))
 		return IRQ_NONE;
 
-	/* Interrupt Auto-Mask...upon reading ICR,
-	 * interrupts are masked.  No need for the
-	 * IMC write, but it does mean we should
-	 * account for it ASAP. */
-	atomic_inc(&adapter->irq_sem);
+	/* Interrupt Auto-Mask...upon reading ICR, interrupts are masked.  No
+	 * need for the IMC write */
 
 	if (icr & (E1000_ICR_RXSEQ | E1000_ICR_LSC)) {
 		hw->mac.get_link_status = 1;
@@ -931,8 +924,6 @@ static irqreturn_t e1000_intr(int irq, void *data)
 		adapter->total_rx_bytes = 0;
 		adapter->total_rx_packets = 0;
 		__netif_rx_schedule(netdev, &adapter->napi);
-	} else {
-		atomic_dec(&adapter->irq_sem);
 	}
 
 	return IRQ_HANDLED;
@@ -983,7 +974,6 @@ static void e1000_irq_disable(struct e1000_adapter *adapter)
 {
 	struct e1000_hw *hw = &adapter->hw;
 
-	atomic_inc(&adapter->irq_sem);
 	ew32(IMC, ~0);
 	e1e_flush();
 	synchronize_irq(adapter->pdev->irq);
@@ -996,10 +986,8 @@ static void e1000_irq_enable(struct e1000_adapter *adapter)
 {
 	struct e1000_hw *hw = &adapter->hw;
 
-	if (atomic_dec_and_test(&adapter->irq_sem)) {
-		ew32(IMS, IMS_ENABLE_MASK);
-		e1e_flush();
-	}
+	ew32(IMS, IMS_ENABLE_MASK);
+	e1e_flush();
 }
 
 /**
@@ -1427,9 +1415,12 @@ static void e1000_vlan_rx_kill_vid(struct net_device *netdev, u16 vid)
 	struct e1000_hw *hw = &adapter->hw;
 	u32 vfta, index;
 
-	e1000_irq_disable(adapter);
+	if (!test_bit(__E1000_DOWN, &adapter->state))
+		e1000_irq_disable(adapter);
 	vlan_group_set_device(adapter->vlgrp, vid, NULL);
-	e1000_irq_enable(adapter);
+
+	if (!test_bit(__E1000_DOWN, &adapter->state))
+		e1000_irq_enable(adapter);
 
 	if ((adapter->hw.mng_cookie.status &
 	     E1000_MNG_DHCP_COOKIE_STATUS_VLAN) &&
@@ -1480,7 +1471,8 @@ static void e1000_vlan_rx_register(struct net_device *netdev,
 	struct e1000_hw *hw = &adapter->hw;
 	u32 ctrl, rctl;
 
-	e1000_irq_disable(adapter);
+	if (!test_bit(__E1000_DOWN, &adapter->state))
+		e1000_irq_disable(adapter);
 	adapter->vlgrp = grp;
 
 	if (grp) {
@@ -1517,7 +1509,8 @@ static void e1000_vlan_rx_register(struct net_device *netdev,
 		}
 	}
 
-	e1000_irq_enable(adapter);
+	if (!test_bit(__E1000_DOWN, &adapter->state))
+		e1000_irq_enable(adapter);
 }
 
 static void e1000_restore_vlan(struct e1000_adapter *adapter)
@@ -2167,7 +2160,6 @@ void e1000e_down(struct e1000_adapter *adapter)
 	msleep(10);
 
 	napi_disable(&adapter->napi);
-	atomic_set(&adapter->irq_sem, 0);
 	e1000_irq_disable(adapter);
 
 	del_timer_sync(&adapter->watchdog_timer);
@@ -2227,7 +2219,6 @@ static int __devinit e1000_sw_init(struct e1000_adapter *adapter)
 	spin_lock_init(&adapter->tx_queue_lock);
 
 	/* Explicitly disable IRQ since the NIC can be in any state. */
-	atomic_set(&adapter->irq_sem, 0);
 	e1000_irq_disable(adapter);
 
 	spin_lock_init(&adapter->stats_lock);