releases/2.6.32.23/r8169-fix-mdio_read-and-update-mdio_write-according-to-hw-specs.patch

From c89e41936cca2f734bd07eb3892a302b98cddd7a Mon Sep 17 00:00:00 2001
From: Timo Teräs <timo.teras@iki.fi>
Date: Wed, 9 Jun 2010 17:31:48 -0700
Subject: r8169: fix mdio_read and update mdio_write according to hw specs


From: Timo Teräs <timo.teras@iki.fi>

[ Upstream commit 81a95f049962ec20a9aed888e676208b206f0f2e ]

Realtek confirmed that a 20us delay is needed after mdio_read and
mdio_write operations. Reduce the delay in mdio_write, and add it
to mdio_read too. Also add a comment that the 20us is from hw specs.

Signed-off-by: Timo Teräs <timo.teras@iki.fi>
Acked-by: Francois Romieu <romieu@fr.zoreil.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
---
 drivers/net/r8169.c |   12 +++++++++---
 1 file changed, 9 insertions(+), 3 deletions(-)

--- a/drivers/net/r8169.c
+++ b/drivers/net/r8169.c
@@ -558,10 +558,10 @@ static void mdio_write(void __iomem *ioa
 		udelay(25);
 	}
 	/*
-	 * Some configurations require a small delay even after the write
-	 * completed indication or the next write might fail.
+	 * According to hardware specs a 20us delay is required after write
+	 * complete indication, but before sending next command.
 	 */
-	udelay(25);
+	udelay(20);
 }
 
 static int mdio_read(void __iomem *ioaddr, int reg_addr)
@@ -581,6 +581,12 @@ static int mdio_read(void __iomem *ioadd
 		}
 		udelay(25);
 	}
+	/*
+	 * According to hardware specs a 20us delay is required after read
+	 * complete indication, but before sending next command.
+	 */
+	udelay(20);
+
 	return value;
 }