[34-longterm 172/179] igb: Fix lack of flush after register write and before delay

From: Paul Gortmaker
Date: Mon May 14 2012 - 22:26:42 EST

From: Carolyn Wyborny <carolyn.wyborny@xxxxxxxxx>

This is a commit scheduled for the next v2.6.34 longterm release.
If you see a problem with using this for longterm, please comment.

commit 064b43304ed8ede8e13ff7b4338d09fd37bcffb1 upstream.

Register writes followed by a delay are required to have a flush
before the delay in order to commit the values to the register. Without
the flush, the code following the delay may not function correctly.

Reported-by: Tong Ho <tong.ho@xxxxxxxxxxxx>
Reported-by: Guenter Roeck <guenter.roeck@xxxxxxxxxxxx>
Signed-off-by: Carolyn Wyborny <carolyn.wyborny@xxxxxxxxx>
Tested-by: Aaron Brown <aaron.f.brown@xxxxxxxxx>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@xxxxxxxxx>
Signed-off-by: Paul Gortmaker <paul.gortmaker@xxxxxxxxxxxxx>
drivers/net/igb/e1000_82575.c | 1 +
1 file changed, 1 insertion(+)

diff --git a/drivers/net/igb/e1000_82575.c b/drivers/net/igb/e1000_82575.c
index 4a32bed..a6ea91d 100644
--- a/drivers/net/igb/e1000_82575.c
+++ b/drivers/net/igb/e1000_82575.c
@@ -1554,6 +1554,7 @@ static s32 igb_reset_hw_82580(struct e1000_hw *hw)
ctrl |= E1000_CTRL_RST;

wr32(E1000_CTRL, ctrl);
+ wrfl();

/* Add delay to insure DEV_RST has time to complete */
if (global_device_reset)

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