[PATCH net-next] igb: reset PHY after recovering from PHY power down

[Koki Sanagi <sanagi.koki@jp.fujitsu.com>]

According to 82576_Datasheet.pdf, PHY setting is lost after PHY power down.
So resetting PHY is needed when recovering from PHY power down to set a default
setting to PHY register.

Owing to this lack, NIC doesn't link up in some rare situation.
The situation I encountered is following.


1.Both ports connect to switch.
+---------+           +--------+
|         |-----------|        |
| 82576NS |           | switch |
|         |-----------|        |
+---------+           +--------+

2.Detach both cables from switch.
+---------+           +--------+
|         |-------    |        |
| 82576NS |           | switch |
|         |-------    |        |
+---------+           +--------+

3.Detach one cable from one port.
+---------+           +--------+
|         |-------    |        |
| 82576NS |           | switch |
|         |           |        |
+---------+           +--------+

4.Attach that cable to the other port.(It means connecting directly each port)
+---------+           +--------+
|         |-------+   |        |
| 82576NS |       |   | switch |
|         |-------+   |        |
+---------+           +--------+

As a result, NIC doesn't link up sometimes.

Signed-off-by: Koki Sanagi <sanagi.koki@jp.fujitsu.com>
---
 drivers/net/ethernet/intel/igb/igb_main.c |    1 +
 1 files changed, 1 insertions(+), 0 deletions(-)

diff --git a/drivers/net/ethernet/intel/igb/igb_main.c b/drivers/net/ethernet/intel/igb/igb_main.c
index bd9b30e..4d4f065 100644
--- a/drivers/net/ethernet/intel/igb/igb_main.c
+++ b/drivers/net/ethernet/intel/igb/igb_main.c
@@ -2496,6 +2496,7 @@ static int igb_open(struct net_device *netdev)
 		goto err_setup_rx;
 
 	igb_power_up_link(adapter);
+	igb_reset_phy(hw);
 
 	/* before we allocate an interrupt, we must be ready to handle it.
 	 * Setting DEBUG_SHIRQ in the kernel makes it fire an interrupt