[e1000] Remove unused variable when ICR register is simply cleared

On reset and close, the ICR register is read to clear any pending
interrupts, but the value is simply ignored.  Avoid assigning the
value to a variable, to inhibit a warning from gcc 4.6.

Also fix a potential race condition in reset routines which clear
interrupts before disabling them.

Reported-by: Ralph Giles <giles@thaumas.net>
Tested-by: Ralph Giles <giles@thaumas.net>
Signed-off-by: Michael Brown <mcb30@ipxe.org>

src/drivers/net/e1000/e1000_82540.c

  **/
 static s32 e1000_reset_hw_82540(struct e1000_hw *hw)
 {
-	u32 ctrl, icr, manc;
+	u32 ctrl, manc;
 	s32 ret_val = E1000_SUCCESS;
 
 	DEBUGFUNC("e1000_reset_hw_82540");
 	E1000_WRITE_REG(hw, E1000_MANC, manc);
 
 	E1000_WRITE_REG(hw, E1000_IMC, 0xffffffff);
-	icr = E1000_READ_REG(hw, E1000_ICR);
+	E1000_READ_REG(hw, E1000_ICR);
 
 	return ret_val;
 }

src/drivers/net/e1000/e1000_82541.c

  **/
 static s32 e1000_reset_hw_82541(struct e1000_hw *hw)
 {
-	u32 ledctl, ctrl, icr, manc;
+	u32 ledctl, ctrl, manc;
 
 	DEBUGFUNC("e1000_reset_hw_82541");
 
 	E1000_WRITE_REG(hw, E1000_IMC, 0xFFFFFFFF);
 
 	/* Clear any pending interrupt events. */
-	icr = E1000_READ_REG(hw, E1000_ICR);
+	E1000_READ_REG(hw, E1000_ICR);
 
 	return E1000_SUCCESS;
 }

src/drivers/net/e1000/e1000_82542.c

 {
 	struct e1000_bus_info *bus = &hw->bus;
 	s32 ret_val = E1000_SUCCESS;
-	u32 ctrl, icr;
+	u32 ctrl;
 
 	DEBUGFUNC("e1000_reset_hw_82542");
 
 	msec_delay(2);
 
 	E1000_WRITE_REG(hw, E1000_IMC, 0xffffffff);
-	icr = E1000_READ_REG(hw, E1000_ICR);
+	E1000_READ_REG(hw, E1000_ICR);
 
 	if (hw->revision_id == E1000_REVISION_2) {
 		if (bus->pci_cmd_word & CMD_MEM_WRT_INVALIDATE)

src/drivers/net/e1000/e1000_82543.c

  **/
 static s32 e1000_reset_hw_82543(struct e1000_hw *hw)
 {
-	u32 ctrl, icr;
+	u32 ctrl;
 	s32 ret_val = E1000_SUCCESS;
 
 	DEBUGFUNC("e1000_reset_hw_82543");
 
 	/* Masking off and clearing any pending interrupts */
 	E1000_WRITE_REG(hw, E1000_IMC, 0xffffffff);
-	icr = E1000_READ_REG(hw, E1000_ICR);
+	E1000_READ_REG(hw, E1000_ICR);
 
 	return ret_val;
 }

src/drivers/net/e1000/e1000_main.c

 	struct e1000_adapter *adapter = netdev_priv ( netdev );
 	struct e1000_hw *hw = &adapter->hw;
 	uint32_t rctl;
-	uint32_t icr;
 
 	DBG ( "e1000_close\n" );
 
-	/* Acknowledge interrupts */
-	icr = E1000_READ_REG ( hw, E1000_ICR );
-
+	/* Disable and acknowledge interrupts */
 	e1000_irq_disable ( adapter );
+	E1000_READ_REG ( hw, E1000_ICR );
 
 	/* disable receives */
 	rctl = E1000_READ_REG ( hw, E1000_RCTL );

src/drivers/net/e1000e/e1000e_80003es2lan.c

  **/
 static s32 e1000e_reset_hw_80003es2lan(struct e1000_hw *hw)
 {
-	u32 ctrl, icr;
+	u32 ctrl;
 	s32 ret_val;
 
 	/*
 
 	/* Clear any pending interrupt events. */
 	ew32(IMC, 0xffffffff);
-	icr = er32(ICR);
+	er32(ICR);
 
 	ret_val = e1000e_check_alt_mac_addr_generic(hw);
 

src/drivers/net/e1000e/e1000e_82571.c

  **/
 static s32 e1000e_reset_hw_82571(struct e1000_hw *hw)
 {
-	u32 ctrl, extcnf_ctrl, ctrl_ext, icr;
+	u32 ctrl, extcnf_ctrl, ctrl_ext;
 	s32 ret_val;
 	u16 i = 0;
 
 
 	/* Clear any pending interrupt events. */
 	ew32(IMC, 0xffffffff);
-	icr = er32(ICR);
+	er32(ICR);
 
 	/* Install any alternate MAC address into RAR0 */
 	ret_val = e1000e_check_alt_mac_addr_generic(hw);

src/drivers/net/e1000e/e1000e_ich8lan.c

 {
 	struct e1000_dev_spec_ich8lan *dev_spec = &hw->dev_spec.ich8lan;
 	u16 reg;
-	u32 ctrl, icr, kab;
+	u32 ctrl, kab;
 	s32 ret_val;
 
 	/*
 		ew32(CRC_OFFSET, 0x65656565);
 
 	ew32(IMC, 0xffffffff);
-	icr = er32(ICR);
+	er32(ICR);
 
 	kab = er32(KABGTXD);
 	kab |= E1000_KABGTXD_BGSQLBIAS;

src/drivers/net/e1000e/e1000e_main.c

 	struct e1000_adapter *adapter = netdev_priv ( netdev );
 	struct e1000_hw *hw = &adapter->hw;
 	uint32_t rctl;
-	uint32_t icr;
 
 	DBGP ( "e1000_close\n" );
 
-	/* Acknowledge interrupts */
-	icr = E1000_READ_REG ( hw, E1000_ICR );
-
+	/* Disable and acknowledge interrupts */
 	e1000e_irq_disable ( adapter );
+	E1000_READ_REG ( hw, E1000_ICR );
 
 	/* disable receives */
 	rctl = E1000_READ_REG ( hw, E1000_RCTL );

src/drivers/net/igb/igb_82575.c

  **/
 static s32 igb_reset_hw_82575(struct e1000_hw *hw)
 {
-	u32 ctrl, icr;
+	u32 ctrl;
 	s32 ret_val;
 
 	DEBUGFUNC("igb_reset_hw_82575");
 
 	/* Clear any pending interrupt events. */
 	E1000_WRITE_REG(hw, E1000_IMC, 0xffffffff);
-	icr = E1000_READ_REG(hw, E1000_ICR);
+	E1000_READ_REG(hw, E1000_ICR);
 
 	/* Install any alternate MAC address into RAR0 */
 	ret_val = igb_check_alt_mac_addr_generic(hw);

src/drivers/net/igb/igb_main.c

 	struct igb_adapter *adapter = netdev_priv ( netdev );
 	struct e1000_hw *hw = &adapter->hw;
 	uint32_t rctl;
-	uint32_t icr;
 
 	DBGP ( "igb_close\n" );
 
-	/* Acknowledge interrupts */
-	icr = E1000_READ_REG ( hw, E1000_ICR );
-
+	/* Disable and acknowledge interrupts */
 	igb_irq_disable ( adapter );
+	E1000_READ_REG ( hw, E1000_ICR );
 
 	/* disable receives */
 	rctl = E1000_READ_REG ( hw, E1000_RCTL );

src/drivers/net/igbvf/igbvf_main.c

 	struct igbvf_adapter *adapter = netdev_priv ( netdev );
         struct e1000_hw *hw = &adapter->hw;
         uint32_t rxdctl;
-        uint32_t icr;
 
         DBG ( "igbvf_close\n" );
-        icr = er32(EICR);
 
+	/* Disable and acknowledge interrupts */
         igbvf_irq_disable ( adapter );
+        er32(EICR);
 
         /* disable receives */
         rxdctl = er32 ( RXDCTL(0) );