[net-next-2.6 PATCH 13/15] igb: add code to retry a phy read in the event of failure on link check

[Jeff Kirsher <jeffrey.t.kirsher@intel.com>]

From: Alexander Duyck <alexander.h.duyck@intel.com>

This patch adds a retry to phy reads in the event of failure.  The original
code broke out of the loop on failure and this is a mistake as we should be
trying to do the read twice.

Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
---

 drivers/net/igb/e1000_phy.c |   10 ++++++++--
 1 files changed, 8 insertions(+), 2 deletions(-)

diff --git a/drivers/net/igb/e1000_phy.c b/drivers/net/igb/e1000_phy.c
index b27275d..5fe03e1 100644
--- a/drivers/net/igb/e1000_phy.c
+++ b/drivers/net/igb/e1000_phy.c
@@ -1444,8 +1444,14 @@ s32 igb_phy_has_link(struct e1000_hw *hw, u32 iterations,
 		 * it across the board.
 		 */
 		ret_val = hw->phy.ops.read_reg(hw, PHY_STATUS, &phy_status);
-		if (ret_val)
-			break;
+		if (ret_val) {
+			/*
+			 * If the first read fails, another entity may have
+			 * ownership of the resources, wait and try again to
+			 * see if they have relinquished the resources yet.
+			 */
+			udelay(usec_interval);
+		}
 		ret_val = hw->phy.ops.read_reg(hw, PHY_STATUS, &phy_status);
 		if (ret_val)
 			break;