3 files changed, 53 insertions, 45 deletions

diff --git a/drivers/net/ethernet/intel/e1000e/e1000.h b/drivers/net/ethernet/intel/e1000e/e1000.h
index b83897f..1dc2067 100644
--- a/drivers/net/ethernet/intel/e1000e/e1000.h
+++ b/drivers/net/ethernet/intel/e1000e/e1000.h
@@ -735,9 +735,46 @@ static inline u32 __er32(struct e1000_hw *hw, unsigned long reg)
 	return readl(hw->hw_addr + reg);
 }
 
+#define er32(reg)	__er32(hw, E1000_##reg)
+
+/**
+ * __ew32_prepare - prepare to write to MAC CSR register on certain parts
+ * @hw: pointer to the HW structure
+ *
+ * When updating the MAC CSR registers, the Manageability Engine (ME) could
+ * be accessing the registers at the same time.  Normally, this is handled in
+ * h/w by an arbiter but on some parts there is a bug that acknowledges Host
+ * accesses later than it should which could result in the register to have
+ * an incorrect value.  Workaround this by checking the FWSM register which
+ * has bit 24 set while ME is accessing MAC CSR registers, wait if it is set
+ * and try again a number of times.
+ **/
+static inline s32 __ew32_prepare(struct e1000_hw *hw)
+{
+	s32 i = E1000_ICH_FWSM_PCIM2PCI_COUNT;
+
+	while ((er32(FWSM) & E1000_ICH_FWSM_PCIM2PCI) && --i)
+		udelay(50);
+
+	return i;
+}
+
 static inline void __ew32(struct e1000_hw *hw, unsigned long reg, u32 val)
 {
+	if (hw->adapter->flags2 & FLAG2_PCIM2PCI_ARBITER_WA)
+		__ew32_prepare(hw);
+
 	writel(val, hw->hw_addr + reg);
 }
 
+#define ew32(reg, val)	__ew32(hw, E1000_##reg, (val))
+
+#define e1e_flush()	er32(STATUS)
+
+#define E1000_WRITE_REG_ARRAY(a, reg, offset, value) \
+	(__ew32((a), (reg + ((offset) << 2)), (value)))
+
+#define E1000_READ_REG_ARRAY(a, reg, offset) \
+	(readl((a)->hw_addr + reg + ((offset) << 2)))
+
 #endif /* _E1000_H_ */
diff --git a/drivers/net/ethernet/intel/e1000e/hw.h b/drivers/net/ethernet/intel/e1000e/hw.h
index 923d3fd..7ca1b68 100644
--- a/drivers/net/ethernet/intel/e1000e/hw.h
+++ b/drivers/net/ethernet/intel/e1000e/hw.h
@@ -36,16 +36,6 @@ struct e1000_adapter;
 
 #include "defines.h"
 
-#define er32(reg)	__er32(hw, E1000_##reg)
-#define ew32(reg,val)	__ew32(hw, E1000_##reg, (val))
-#define e1e_flush()	er32(STATUS)
-
-#define E1000_WRITE_REG_ARRAY(a, reg, offset, value) \
-	(writel((value), ((a)->hw_addr + reg + ((offset) << 2))))
-
-#define E1000_READ_REG_ARRAY(a, reg, offset) \
-	(readl((a)->hw_addr + reg + ((offset) << 2)))
-
 enum e1e_registers {
 	E1000_CTRL     = 0x00000, /* Device Control - RW */
 	E1000_STATUS   = 0x00008, /* Device Status - RO */
diff --git a/drivers/net/ethernet/intel/e1000e/netdev.c b/drivers/net/ethernet/intel/e1000e/netdev.c
index 851f793..cdfb1d6 100644
--- a/drivers/net/ethernet/intel/e1000e/netdev.c
+++ b/drivers/net/ethernet/intel/e1000e/netdev.c
@@ -538,43 +538,15 @@ static void e1000_rx_checksum(struct e1000_adapter *adapter, u32 status_err,
 	adapter->hw_csum_good++;
 }
 
-/**
- * e1000e_update_tail_wa - helper function for e1000e_update_[rt]dt_wa()
- * @hw: pointer to the HW structure
- * @tail: address of tail descriptor register
- * @i: value to write to tail descriptor register
- *
- * When updating the tail register, the ME could be accessing Host CSR
- * registers at the same time.  Normally, this is handled in h/w by an
- * arbiter but on some parts there is a bug that acknowledges Host accesses
- * later than it should which could result in the descriptor register to
- * have an incorrect value.  Workaround this by checking the FWSM register
- * which has bit 24 set while ME is accessing Host CSR registers, wait
- * if it is set and try again a number of times.
- **/
-static inline s32 e1000e_update_tail_wa(struct e1000_hw *hw, void __iomem *tail,
-					unsigned int i)
-{
-	unsigned int j = 0;
-
-	while ((j++ < E1000_ICH_FWSM_PCIM2PCI_COUNT) &&
-	       (er32(FWSM) & E1000_ICH_FWSM_PCIM2PCI))
-		udelay(50);
-
-	writel(i, tail);
-
-	if ((j == E1000_ICH_FWSM_PCIM2PCI_COUNT) && (i != readl(tail)))
-		return E1000_ERR_SWFW_SYNC;
-
-	return 0;
-}
-
 static void e1000e_update_rdt_wa(struct e1000_ring *rx_ring, unsigned int i)
 {
 	struct e1000_adapter *adapter = rx_ring->adapter;
 	struct e1000_hw *hw = &adapter->hw;
+	s32 ret_val = __ew32_prepare(hw);
+
+	writel(i, rx_ring->tail);
 
-	if (e1000e_update_tail_wa(hw, rx_ring->tail, i)) {
+	if (unlikely(!ret_val && (i != readl(rx_ring->tail)))) {
 		u32 rctl = er32(RCTL);
 		ew32(RCTL, rctl & ~E1000_RCTL_EN);
 		e_err("ME firmware caused invalid RDT - resetting\n");
@@ -586,8 +558,11 @@ static void e1000e_update_tdt_wa(struct e1000_ring *tx_ring, unsigned int i)
 {
 	struct e1000_adapter *adapter = tx_ring->adapter;
 	struct e1000_hw *hw = &adapter->hw;
+	s32 ret_val = __ew32_prepare(hw);
 
-	if (e1000e_update_tail_wa(hw, tx_ring->tail, i)) {
+	writel(i, tx_ring->tail);
+
+	if (unlikely(!ret_val && (i != readl(tx_ring->tail)))) {
 		u32 tctl = er32(TCTL);
 		ew32(TCTL, tctl & ~E1000_TCTL_EN);
 		e_err("ME firmware caused invalid TDT - resetting\n");
@@ -1646,7 +1621,10 @@ static void e1000_clean_rx_ring(struct e1000_ring *rx_ring)
 	adapter->flags2 &= ~FLAG2_IS_DISCARDING;
 
 	writel(0, rx_ring->head);
-	writel(0, rx_ring->tail);
+	if (rx_ring->adapter->flags2 & FLAG2_PCIM2PCI_ARBITER_WA)
+		e1000e_update_rdt_wa(rx_ring, 0);
+	else
+		writel(0, rx_ring->tail);
 }
 
 static void e1000e_downshift_workaround(struct work_struct *work)
@@ -2319,7 +2297,10 @@ static void e1000_clean_tx_ring(struct e1000_ring *tx_ring)
 	tx_ring->next_to_clean = 0;
 
 	writel(0, tx_ring->head);
-	writel(0, tx_ring->tail);
+	if (tx_ring->adapter->flags2 & FLAG2_PCIM2PCI_ARBITER_WA)
+		e1000e_update_tdt_wa(tx_ring, 0);
+	else
+		writel(0, tx_ring->tail);
 }
 
 /**