e1000e: 82571 check for link fix on 82571 serdes

Check for link test does not work properly for 82571 parts in a blade
environment with an unterminated serdes link partner.  Make the test more
robust by checking the invalid bit.

Signed-off-by: Bruce Allan <bruce.w.allan@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 28 insertions, 6 deletions

diff --git a/drivers/net/e1000e/lib.c b/drivers/net/e1000e/lib.c
index 089578f6855a..37753d13cd22 100644
--- a/drivers/net/e1000e/lib.c
+++ b/drivers/net/e1000e/lib.c
@@ -575,20 +575,42 @@ s32 e1000e_check_for_serdes_link(struct e1000_hw *hw)
                  */
                 /* SYNCH bit and IV bit are sticky. */
                 udelay(10);
-                if (E1000_RXCW_SYNCH & er32(RXCW)) {
+                rxcw = er32(RXCW);
+                if (rxcw & E1000_RXCW_SYNCH) {
                         if (!(rxcw & E1000_RXCW_IV)) {
-                                mac->serdes_has_link = 1;
-                                hw_dbg(hw, "SERDES: Link is up.\n");
+                                mac->serdes_has_link = true;
+                                hw_dbg(hw, "SERDES: Link up - forced.\n");
                         }
                 } else {
-                        mac->serdes_has_link = 0;
-                        hw_dbg(hw, "SERDES: Link is down.\n");
+                        mac->serdes_has_link = false;
+                        hw_dbg(hw, "SERDES: Link down - force failed.\n");
                 }
         }
 
         if (E1000_TXCW_ANE & er32(TXCW)) {
                 status = er32(STATUS);
-                mac->serdes_has_link = (status & E1000_STATUS_LU);
+                if (status & E1000_STATUS_LU) {
+                        /* SYNCH bit and IV bit are sticky, so reread rxcw.  */
+                        udelay(10);
+                        rxcw = er32(RXCW);
+                        if (rxcw & E1000_RXCW_SYNCH) {
+                                if (!(rxcw & E1000_RXCW_IV)) {
+                                        mac->serdes_has_link = true;
+                                        hw_dbg(hw, "SERDES: Link up - autoneg "
+                                           "completed sucessfully.\n");
+                                } else {
+                                        mac->serdes_has_link = false;
+                                        hw_dbg(hw, "SERDES: Link down - invalid"
+                                           "codewords detected in autoneg.\n");
+                                }
+                        } else {
+                                mac->serdes_has_link = false;
+                                hw_dbg(hw, "SERDES: Link down - no sync.\n");
+                        }
+                } else {
+                        mac->serdes_has_link = false;
+                        hw_dbg(hw, "SERDES: Link down - autoneg failed\n");
+                }
         }
 
         return 0;