ixgbe: fix register access during ethtool loopback test

This patch cleans up the logic in ixgbe_setup_loopback_test() to only access
registers applicable to the MAC type. AUTOC is only valid on MACs older than
X540. MACC is used for X540.

In addition it removes a read of AUTOC and uses the stored value to force the
link up.

Signed-off-by: Emil Tantilov <emil.s.tantilov@intel.com>
Tested-by: Phil Schmitt <phillip.j.schmitt@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

1 files changed, 14 insertions, 12 deletions

diff --git a/drivers/net/ethernet/intel/ixgbe/ixgbe_ethtool.c b/drivers/net/ethernet/intel/ixgbe/ixgbe_ethtool.c
index bbe00bcc7582..509d3ae191f3 100644
--- a/drivers/net/ethernet/intel/ixgbe/ixgbe_ethtool.c
+++ b/drivers/net/ethernet/intel/ixgbe/ixgbe_ethtool.c
@@ -1609,16 +1609,9 @@ static int ixgbe_setup_loopback_test(struct ixgbe_adapter *adapter)
         struct ixgbe_hw *hw = &adapter->hw;
         u32 reg_data;
 
-        /* X540 needs to set the MACC.FLU bit to force link up */
-        if (adapter->hw.mac.type == ixgbe_mac_X540) {
-                reg_data = IXGBE_READ_REG(hw, IXGBE_MACC);
-                reg_data |= IXGBE_MACC_FLU;
-                IXGBE_WRITE_REG(hw, IXGBE_MACC, reg_data);
-        }
 
-        /* right now we only support MAC loopback in the driver */
-        reg_data = IXGBE_READ_REG(hw, IXGBE_HLREG0);
         /* Setup MAC loopback */
+        reg_data = IXGBE_READ_REG(hw, IXGBE_HLREG0);
         reg_data |= IXGBE_HLREG0_LPBK;
         IXGBE_WRITE_REG(hw, IXGBE_HLREG0, reg_data);
 
@@ -1626,10 +1619,19 @@ static int ixgbe_setup_loopback_test(struct ixgbe_adapter *adapter)
         reg_data |= IXGBE_FCTRL_BAM | IXGBE_FCTRL_SBP | IXGBE_FCTRL_MPE;
         IXGBE_WRITE_REG(hw, IXGBE_FCTRL, reg_data);
 
-        reg_data = IXGBE_READ_REG(hw, IXGBE_AUTOC);
-        reg_data &= ~IXGBE_AUTOC_LMS_MASK;
-        reg_data |= IXGBE_AUTOC_LMS_10G_LINK_NO_AN | IXGBE_AUTOC_FLU;
-        IXGBE_WRITE_REG(hw, IXGBE_AUTOC, reg_data);
+        /* X540 needs to set the MACC.FLU bit to force link up */
+        if (adapter->hw.mac.type == ixgbe_mac_X540) {
+                reg_data = IXGBE_READ_REG(hw, IXGBE_MACC);
+                reg_data |= IXGBE_MACC_FLU;
+                IXGBE_WRITE_REG(hw, IXGBE_MACC, reg_data);
+        } else {
+                if (hw->mac.orig_autoc) {
+                        reg_data = hw->mac.orig_autoc | IXGBE_AUTOC_FLU;
+                        IXGBE_WRITE_REG(hw, IXGBE_AUTOC, reg_data);
+                } else {
+                        return 10;
+                }
+        }
         IXGBE_WRITE_FLUSH(hw);
         usleep_range(10000, 20000);