* Due to HW bug, LAN8700 sometimes does not detect presence of energy in the
  Ethernet cable in Energy Detect Power-Down mode (e.g while EDPWRDOWN bit is
  set, the ENERGYON bit does not asserted sometimes). This is a common bug of
  LAN87xx family of PHY chips.
* The lan87xx_read_status() was improved to acquire ENERGYON bit. Its previous
  algorythm still not reliable on 100 % and sometimes skip cable plugging.

Signed-off-by: Igor Plyatov <plya...@gmail.com>
---
 drivers/net/phy/smsc.c |   15 ++++++++++++---
 1 file changed, 12 insertions(+), 3 deletions(-)

diff --git a/drivers/net/phy/smsc.c b/drivers/net/phy/smsc.c
index c0f6479..8559ff1 100644
--- a/drivers/net/phy/smsc.c
+++ b/drivers/net/phy/smsc.c
@@ -104,6 +104,7 @@ static int lan911x_config_init(struct phy_device *phydev)
 static int lan87xx_read_status(struct phy_device *phydev)
 {
        int err = genphy_read_status(phydev);
+       int i;
 
        if (!phydev->link) {
                /* Disable EDPD to wake up PHY */
@@ -116,8 +117,16 @@ static int lan87xx_read_status(struct phy_device *phydev)
                if (rc < 0)
                        return rc;
 
-               /* Sleep 64 ms to allow ~5 link test pulses to be sent */
-               msleep(64);
+               /* Wait max 640 ms to detect energy */
+               for (i = 0; i < 64; i++) {
+                       /* Sleep to allow link test pulses to be sent */
+                       msleep(10);
+                       rc = phy_read(phydev, MII_LAN83C185_CTRL_STATUS);
+                       if (rc < 0)
+                               return rc;
+                       if (rc & MII_LAN83C185_ENERGYON)
+                               break;
+               };
 
                /* Re-enable EDPD */
                rc = phy_read(phydev, MII_LAN83C185_CTRL_STATUS);
@@ -191,7 +200,7 @@ static struct phy_driver smsc_phy_driver[] = {
 
        /* basic functions */
        .config_aneg    = genphy_config_aneg,
-       .read_status    = genphy_read_status,
+       .read_status    = lan87xx_read_status,
        .config_init    = smsc_phy_config_init,
        .soft_reset     = smsc_phy_reset,
 
-- 
1.7.9.5

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