[ 26/37] e1000e: NIC goes up and immediately goes down

[Ben Hutchings]

3.2-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Tushar Dave <tushar.n.dave@xxxxxxxxx>

commit b7ec70be01a87f2c85df3ae11046e74f9b67e323 upstream.

Found that commit d478eb44 was a bad commit.
If the link partner is transmitting codeword (even if NULL codeword),
then the RXCW.C bit will be set so check for RXCW.CW is unnecessary.
Ref: RH BZ 840642

Reported-by: Fabio Futigami <ffutigam@xxxxxxxxxx>
Signed-off-by: Tushar Dave <tushar.n.dave@xxxxxxxxx>
CC: Marcelo Ricardo Leitner <mleitner@xxxxxxxxxx>
Tested-by: Aaron Brown <aaron.f.brown@xxxxxxxxx>
Signed-off-by: Peter P Waskiewicz Jr <peter.p.waskiewicz.jr@xxxxxxxxx>
Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx>
---
 drivers/net/ethernet/intel/e1000e/82571.c |    4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/drivers/net/ethernet/intel/e1000e/82571.c b/drivers/net/ethernet/intel/e1000e/82571.c
index 0b3bade..2a4ded2 100644
--- a/drivers/net/ethernet/intel/e1000e/82571.c
+++ b/drivers/net/ethernet/intel/e1000e/82571.c
@@ -1601,10 +1601,8 @@ static s32 e1000_check_for_serdes_link_82571(struct e1000_hw *hw)
 			 * auto-negotiation in the TXCW register and disable
 			 * forced link in the Device Control register in an
 			 * attempt to auto-negotiate with our link partner.
-			 * If the partner code word is null, stop forcing
-			 * and restart auto negotiation.
 			 */
-			if ((rxcw & E1000_RXCW_C) || !(rxcw & E1000_RXCW_CW))  {
+			if (rxcw & E1000_RXCW_C) {
 				/* Enable autoneg, and unforce link up */
 				ew32(TXCW, mac->txcw);
 				ew32(CTRL, (ctrl & ~E1000_CTRL_SLU));


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