[U-Boot] [PATCH] phy: Check return value for read MII_STAT1000 register

[Nobuhiro Iwamatsu]

When Extended register is effective, there is not necessarily certainly
register for 1000BASE. 0xFFFF may be able to be read although register
is read. This adds this check.

Signed-off-by: Nobuhiro Iwamatsu <nobuhiro.iwamatsu.yj at renesas.com>
---
 drivers/net/phy/phy.c |    8 +++++++-
 1 files changed, 7 insertions(+), 1 deletions(-)

diff --git a/drivers/net/phy/phy.c b/drivers/net/phy/phy.c
index 8da7688..f0b3c56 100644
--- a/drivers/net/phy/phy.c
+++ b/drivers/net/phy/phy.c
@@ -294,8 +294,14 @@ static int genphy_parse_link(struct phy_device *phydev)
 			 * both PHYs in the link
 			 */
 			gblpa = phy_read(phydev, MDIO_DEVAD_NONE, MII_STAT1000);
-			gblpa &= phy_read(phydev,
+			/* If gblpa was 0xFFFF or -1, this chip does not have MII_STAT1000
+			   register or read error. */
+			if (gblpa == 0xFFFF | gblpa == -1) {
+				gblpa = 0;
+			} else {
+				gblpa &= phy_read(phydev,
 					MDIO_DEVAD_NONE, MII_CTRL1000) << 2;
+			}
 		}
 
 		/* Set the baseline so we only have to set them
-- 
1.7.7