sfc: Fix unreliable link detection in some loopback modes

Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 13 insertions, 9 deletions

diff --git a/drivers/net/sfc/mdio_10g.c b/drivers/net/sfc/mdio_10g.c
index 037601e0b9d7..f131ad2b6832 100644
--- a/drivers/net/sfc/mdio_10g.c
+++ b/drivers/net/sfc/mdio_10g.c
@@ -167,7 +167,7 @@ int mdio_clause45_check_mmds(struct efx_nic *efx,
 bool mdio_clause45_links_ok(struct efx_nic *efx, unsigned int mmd_mask)
 {
         int phy_id = efx->mii.phy_id;
-        int status;
+        u32 reg;
         bool ok = true;
         int mmd = 0;
 
@@ -179,12 +179,17 @@ bool mdio_clause45_links_ok(struct efx_nic *efx, unsigned int mmd_mask)
                 return false;
         else if (efx_phy_mode_disabled(efx->phy_mode))
                 return false;
-        else if (efx->loopback_mode == LOOPBACK_PHYXS)
+        else if (efx->loopback_mode == LOOPBACK_PHYXS) {
                 mmd_mask &= ~(MDIO_MMDREG_DEVS_PHYXS |
                               MDIO_MMDREG_DEVS_PCS |
                               MDIO_MMDREG_DEVS_PMAPMD |
                               MDIO_MMDREG_DEVS_AN);
-        else if (efx->loopback_mode == LOOPBACK_PCS)
+                if (!mmd_mask) {
+                        reg = mdio_clause45_read(efx, phy_id, MDIO_MMD_PHYXS,
+                                                 MDIO_PHYXS_STATUS2);
+                        return !(reg & (1 << MDIO_PHYXS_STATUS2_RX_FAULT_LBN));
+                }
+        } else if (efx->loopback_mode == LOOPBACK_PCS)
                 mmd_mask &= ~(MDIO_MMDREG_DEVS_PCS |
                               MDIO_MMDREG_DEVS_PMAPMD |
                               MDIO_MMDREG_DEVS_AN);
@@ -196,12 +201,11 @@ bool mdio_clause45_links_ok(struct efx_nic *efx, unsigned int mmd_mask)
                 if (mmd_mask & 1) {
                         /* Double reads because link state is latched, and a
                          * read moves the current state into the register */
-                        status = mdio_clause45_read(efx, phy_id,
-                                                    mmd, MDIO_MMDREG_STAT1);
-                        status = mdio_clause45_read(efx, phy_id,
-                                                    mmd, MDIO_MMDREG_STAT1);
-
-                        ok = ok && (status & (1 << MDIO_MMDREG_STAT1_LINK_LBN));
+                        reg = mdio_clause45_read(efx, phy_id,
+                                                 mmd, MDIO_MMDREG_STAT1);
+                        reg = mdio_clause45_read(efx, phy_id,
+                                                 mmd, MDIO_MMDREG_STAT1);
+                        ok = ok && (reg & (1 << MDIO_MMDREG_STAT1_LINK_LBN));
                 }
                 mmd_mask = (mmd_mask >> 1);
                 mmd++;