1 files changed, 21 insertions, 8 deletions

diff --git a/drivers/net/ethernet/freescale/xgmac_mdio.c b/drivers/net/ethernet/freescale/xgmac_mdio.c
index 0b68852379da..266e562bd67a 100644
--- a/drivers/net/ethernet/freescale/xgmac_mdio.c
+++ b/drivers/net/ethernet/freescale/xgmac_mdio.c
@@ -47,11 +47,11 @@ struct tgec_mdio_controller {
 #define MDIO_CTL_READ		BIT(15)
 
 #define MDIO_DATA(x)		(x & 0xffff)
-#define MDIO_DATA_BSY		BIT(31)
 
 struct mdio_fsl_priv {
 	struct	tgec_mdio_controller __iomem *mdio_base;
 	bool	is_little_endian;
+	bool	has_a009885;
 	bool	has_a011043;
 };
 
@@ -187,10 +187,10 @@ static int xgmac_mdio_read(struct mii_bus *bus, int phy_id, int regnum)
 {
 	struct mdio_fsl_priv *priv = (struct mdio_fsl_priv *)bus->priv;
 	struct tgec_mdio_controller __iomem *regs = priv->mdio_base;
+	unsigned long flags;
 	uint16_t dev_addr;
 	uint32_t mdio_stat;
 	uint32_t mdio_ctl;
-	uint16_t value;
 	int ret;
 	bool endian = priv->is_little_endian;
 
@@ -222,12 +222,18 @@ static int xgmac_mdio_read(struct mii_bus *bus, int phy_id, int regnum)
 			return ret;
 	}
 
+	if (priv->has_a009885)
+		/* Once the operation completes, i.e. MDIO_STAT_BSY clears, we
+		 * must read back the data register within 16 MDC cycles.
+		 */
+		local_irq_save(flags);
+
 	/* Initiate the read */
 	xgmac_write32(mdio_ctl | MDIO_CTL_READ, &regs->mdio_ctl, endian);
 
 	ret = xgmac_wait_until_done(&bus->dev, regs, endian);
 	if (ret)
-		return ret;
+		goto irq_restore;
 
 	/* Return all Fs if nothing was there */
 	if ((xgmac_read32(&regs->mdio_stat, endian) & MDIO_STAT_RD_ER) &&
@@ -235,13 +241,17 @@ static int xgmac_mdio_read(struct mii_bus *bus, int phy_id, int regnum)
 		dev_dbg(&bus->dev,
 			"Error while reading PHY%d reg at %d.%hhu\n",
 			phy_id, dev_addr, regnum);
-		return 0xffff;
+		ret = 0xffff;
+	} else {
+		ret = xgmac_read32(&regs->mdio_data, endian) & 0xffff;
+		dev_dbg(&bus->dev, "read %04x\n", ret);
 	}
 
-	value = xgmac_read32(&regs->mdio_data, endian) & 0xffff;
-	dev_dbg(&bus->dev, "read %04x\n", value);
+irq_restore:
+	if (priv->has_a009885)
+		local_irq_restore(flags);
 
-	return value;
+	return ret;
 }
 
 static int xgmac_mdio_probe(struct platform_device *pdev)
@@ -288,6 +298,8 @@ static int xgmac_mdio_probe(struct platform_device *pdev)
 	priv->is_little_endian = device_property_read_bool(&pdev->dev,
 							   "little-endian");
 
+	priv->has_a009885 = device_property_read_bool(&pdev->dev,
+						      "fsl,erratum-a009885");
 	priv->has_a011043 = device_property_read_bool(&pdev->dev,
 						      "fsl,erratum-a011043");
 
@@ -319,9 +331,10 @@ err_ioremap:
 static int xgmac_mdio_remove(struct platform_device *pdev)
 {
 	struct mii_bus *bus = platform_get_drvdata(pdev);
+	struct mdio_fsl_priv *priv = bus->priv;
 
 	mdiobus_unregister(bus);
-	iounmap(bus->priv);
+	iounmap(priv->mdio_base);
 	mdiobus_free(bus);
 
 	return 0;