From: Emil Tantilov <emil.s.tanti...@intel.com>
Read the PHY register twice in order to get the correct value for
autoneg_status.
Signed-off-by: Emil Tantilov <emil.s.tanti...@intel.com>
Tested-by: Krishneil Singh <krishneil.k.si...@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirs...@intel.com>
---
drivers/net/ethernet/intel/ixgbe/ixgbe_x550.c | 21 +++++++++++++--------
1 file changed, 13 insertions(+), 8 deletions(-)
diff --git a/drivers/net/ethernet/intel/ixgbe/ixgbe_x550.c
b/drivers/net/ethernet/intel/ixgbe/ixgbe_x550.c
index e9fa83b..51b6ade 100644
--- a/drivers/net/ethernet/intel/ixgbe/ixgbe_x550.c
+++ b/drivers/net/ethernet/intel/ixgbe/ixgbe_x550.c
@@ -1556,7 +1556,7 @@ static s32 ixgbe_check_link_t_X550em(struct ixgbe_hw *hw,
bool link_up_wait_to_complete)
{
u32 status;
- u16 autoneg_status;
+ u16 i, autoneg_status;
if (hw->mac.ops.get_media_type(hw) != ixgbe_media_type_copper)
return IXGBE_ERR_CONFIG;
@@ -1568,13 +1568,18 @@ static s32 ixgbe_check_link_t_X550em(struct ixgbe_hw
*hw,
if (status || !(*link_up))
return status;
- /* MAC link is up, so check external PHY link.
- * Read this twice back to back to indicate current status.
- */
- status = hw->phy.ops.read_reg(hw, MDIO_STAT1, MDIO_MMD_AN,
- &autoneg_status);
- if (status)
- return status;
+ /* MAC link is up, so check external PHY link.
+ * Link status is latching low, and can only be used to detect link
+ * drop, and not the current status of the link without performing
+ * back-to-back reads.
+ */
+ for (i = 0; i < 2; i++) {
+ status = hw->phy.ops.read_reg(hw, MDIO_STAT1, MDIO_MMD_AN,
+ &autoneg_status);
+
+ if (status)
+ return status;
+ }
/* If external PHY link is not up, then indicate link not up */
if (!(autoneg_status & IXGBE_MDIO_AUTO_NEG_LINK_STATUS))
--
2.7.4
