From d0efa8f23a644f7cb7d1f8e78dd9a223efa412a3 Mon Sep 17 00:00:00 2001 From: Tushar Dave Date: Thu, 12 Jul 2012 08:56:56 +0000 Subject: e1000e: Correct link check logic for 82571 serdes SYNCH bit and IV bit of RXCW register are sticky. Before examining these bits, RXCW should be read twice to filter out one-time false events and have correct values for these bits. Incorrect values of these bits in link check logic can cause weird link stability issues if auto-negotiation fails. CC: stable [2.6.38+] Reported-by: Dean Nelson Signed-off-by: Tushar Dave Reviewed-by: Bruce Allan Tested-by: Jeff Pieper Signed-off-by: Jeff Kirsher --- drivers/net/ethernet/intel/e1000e/82571.c | 3 +++ 1 file changed, 3 insertions(+) (limited to 'drivers/net/ethernet/intel/e1000e/82571.c') diff --git a/drivers/net/ethernet/intel/e1000e/82571.c b/drivers/net/ethernet/intel/e1000e/82571.c index 36db4df09aed..1f063dcd8f85 100644 --- a/drivers/net/ethernet/intel/e1000e/82571.c +++ b/drivers/net/ethernet/intel/e1000e/82571.c @@ -1572,6 +1572,9 @@ static s32 e1000_check_for_serdes_link_82571(struct e1000_hw *hw) ctrl = er32(CTRL); status = er32(STATUS); rxcw = er32(RXCW); + /* SYNCH bit and IV bit are sticky */ + udelay(10); + rxcw = er32(RXCW); if ((rxcw & E1000_RXCW_SYNCH) && !(rxcw & E1000_RXCW_IV)) { -- cgit v1.2.3 From 18115f82bc93094a3554f3013cc314ee366a6e7a Mon Sep 17 00:00:00 2001 From: Tushar Dave Date: Thu, 12 Jul 2012 08:00:15 +0000 Subject: e1000e: Cleanup code logic in e1000_check_for_serdes_link_82571() Cleanup code to make it more clean and readable. Signed-off-by: Tushar Dave Tested-by: Aaron Brown Signed-off-by: Jeff Kirsher --- drivers/net/ethernet/intel/e1000e/82571.c | 14 ++++++++------ 1 file changed, 8 insertions(+), 6 deletions(-) (limited to 'drivers/net/ethernet/intel/e1000e/82571.c') diff --git a/drivers/net/ethernet/intel/e1000e/82571.c b/drivers/net/ethernet/intel/e1000e/82571.c index 36db4df09aed..19f4cb9582b5 100644 --- a/drivers/net/ethernet/intel/e1000e/82571.c +++ b/drivers/net/ethernet/intel/e1000e/82571.c @@ -1677,16 +1677,18 @@ static s32 e1000_check_for_serdes_link_82571(struct e1000_hw *hw) e_dbg("ANYSTATE -> DOWN\n"); } else { /* - * Check several times, if Sync and Config - * both are consistently 1 then simply ignore - * the Invalid bit and restart Autoneg + * Check several times, if SYNCH bit and CONFIG + * bit both are consistently 1 then simply ignore + * the IV bit and restart Autoneg */ for (i = 0; i < AN_RETRY_COUNT; i++) { udelay(10); rxcw = er32(RXCW); - if ((rxcw & E1000_RXCW_IV) && - !((rxcw & E1000_RXCW_SYNCH) && - (rxcw & E1000_RXCW_C))) { + if ((rxcw & E1000_RXCW_SYNCH) && + (rxcw & E1000_RXCW_C)) + continue; + + if (rxcw & E1000_RXCW_IV) { mac->serdes_has_link = false; mac->serdes_link_state = e1000_serdes_link_down; -- cgit v1.2.3