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

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Message-ID: <20091005163522.32487.5411.stgit@localhost.localdomain>
Date:	Mon, 05 Oct 2009 09:35:23 -0700
From:	Jeff Kirsher <jeffrey.t.kirsher@...el.com>
To:	davem@...emloft.net
Cc:	netdev@...r.kernel.org, gospo@...hat.com,
	Alexander Duyck <alexander.h.duyck@...el.com>,
	Jeff Kirsher <jeffrey.t.kirsher@...el.com>
Subject: [net-next-2.6 PATCH 13/15] igb: add code to retry a phy read in the
	event of failure on link check

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

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