e1000e: NIC goes up and immediately goes down

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 <[email protected]>
Signed-off-by: Tushar Dave <[email protected]>
CC: Marcelo Ricardo Leitner <[email protected]>
CC: stable <[email protected]> [2.6.38+]
Tested-by: Aaron Brown <[email protected]>
Signed-off-by: Peter P Waskiewicz Jr <[email protected]>

diff --git a/drivers/net/ethernet/intel/e1000e/82571.c b/drivers/net/ethernet/intel/e1000e/82571.c
index 0b3bade957fd8424f59f16ff6e5e27a7c0b6058e..2a4ded2fd6e570ea7c47941425dd2b4e8c81d24c 100644 (file)
--- 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));