mdio: Check MDIO_STAT1_FAULT in mdio45_links_ok()

Some PHYs will report that the link is up even though there is a fault
condition.  Therefore, check the fault flag too.  We must also read
STAT2 to reset this flag.

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

1 files changed, 10 insertions, 3 deletions

diff --git a/drivers/net/mdio.c b/drivers/net/mdio.c
index 6851bdb2ce29..7d2e610f14ff 100644
--- a/drivers/net/mdio.c
+++ b/drivers/net/mdio.c
@@ -109,13 +109,20 @@ int mdio45_links_ok(const struct mdio_if_info *mdio, u32 mmd_mask)
                 if (mmd_mask & (1 << devad)) {
                         mmd_mask &= ~(1 << devad);
 
-                        /* Read twice because link state is latched and a
-                         * read moves the current state into the register */
+                        /* Reset the latched status and fault flags */
                         mdio->mdio_read(mdio->dev, mdio->prtad,
                                         devad, MDIO_STAT1);
+                        if (devad == MDIO_MMD_PMAPMD || devad == MDIO_MMD_PCS ||
+                            devad == MDIO_MMD_PHYXS || devad == MDIO_MMD_DTEXS)
+                                mdio->mdio_read(mdio->dev, mdio->prtad,
+                                                devad, MDIO_STAT2);
+
+                        /* Check the current status and fault flags */
                         reg = mdio->mdio_read(mdio->dev, mdio->prtad,
                                               devad, MDIO_STAT1);
-                        if (reg < 0 || !(reg & MDIO_STAT1_LSTATUS))
+                        if (reg < 0 ||
+                            (reg & (MDIO_STAT1_FAULT | MDIO_STAT1_LSTATUS)) !=
+                            MDIO_STAT1_LSTATUS)
                                 return false;
                 }
         }