[34-longterm 152/196] e1000e: Reset 82577/82578 PHY before first PHY register read

[Paul Gortmaker]

From: Bruce Allan <bruce.w.allan@xxxxxxxxx>

                   -------------------
    This is a commit scheduled for the next v2.6.34 longterm release.
    If you see a problem with using this for longterm, please comment.
                   -------------------

commit 627c8a041f7aaaea93c766f69bd61d952a277586 upstream.

Reset the PHY before first accessing it.  Doing so, ensure that the PHY is
in a known good state before we read/write PHY registers. This fixes a
driver probe failure.

Signed-off-by: Bruce Allan <bruce.w.allan@xxxxxxxxx>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@xxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Paul Gortmaker <paul.gortmaker@xxxxxxxxxxxxx>
---
 drivers/net/e1000e/ich8lan.c |   10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/drivers/net/e1000e/ich8lan.c b/drivers/net/e1000e/ich8lan.c
index 8b5e157..a626012 100644
--- a/drivers/net/e1000e/ich8lan.c
+++ b/drivers/net/e1000e/ich8lan.c
@@ -274,6 +274,16 @@ static s32 e1000_init_phy_params_pchlan(struct e1000_hw *hw)
 	phy->ops.power_down           = e1000_power_down_phy_copper_ich8lan;
 	phy->autoneg_mask             = AUTONEG_ADVERTISE_SPEED_DEFAULT;
 
+	/*
+	 * Reset the PHY before any acccess to it.  Doing so, ensures that
+	 * the PHY is in a known good state before we read/write PHY registers.
+	 * The generic reset is sufficient here, because we haven't determined
+	 * the PHY type yet.
+	 */
+	ret_val = e1000e_phy_hw_reset_generic(hw);
+	if (ret_val)
+		goto out;
+
 	phy->id = e1000_phy_unknown;
 	ret_val = e1000e_get_phy_id(hw);
 	if (ret_val)
-- 
1.7.9.3

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