1 files changed, 59 insertions, 57 deletions

diff --git a/drivers/net/ethernet/marvell/mvmdio.c b/drivers/net/ethernet/marvell/mvmdio.c
index e2f662660313..c4eeb69a5bee 100644
--- a/drivers/net/ethernet/marvell/mvmdio.c
+++ b/drivers/net/ethernet/marvell/mvmdio.c
@@ -4,11 +4,9 @@
  * Since the MDIO interface of Marvell network interfaces is shared
  * between all network interfaces, having a single driver allows to
  * handle concurrent accesses properly (you may have four Ethernet
- * ports, but they in fact share the same SMI interface to access the
- * MDIO bus). Moreover, this MDIO interface code is similar between
- * the mv643xx_eth driver and the mvneta driver. For now, it is only
- * used by the mvneta driver, but it could later be used by the
- * mv643xx_eth driver as well.
+ * ports, but they in fact share the same SMI interface to access
+ * the MDIO bus). This driver is currently used by the mvneta and
+ * mv643xx_eth drivers.
  *
  * Copyright (C) 2012 Marvell
  *
@@ -44,6 +42,15 @@
 #define  MVMDIO_ERR_INT_SMI_DONE	   0x00000010
 #define MVMDIO_ERR_INT_MASK		   0x0080
 
+/*
+ * SMI Timeout measurements:
+ * - Kirkwood 88F6281 (Globalscale Dreamplug): 45us to 95us (Interrupt)
+ * - Armada 370       (Globalscale Mirabox):   41us to 43us (Polled)
+ */
+#define MVMDIO_SMI_TIMEOUT		   1000 /* 1000us = 1ms */
+#define MVMDIO_SMI_POLL_INTERVAL_MIN	   45
+#define MVMDIO_SMI_POLL_INTERVAL_MAX	   55
+
 struct orion_mdio_dev {
 	struct mutex lock;
 	void __iomem *regs;
@@ -68,77 +75,74 @@ static int orion_mdio_smi_is_done(struct orion_mdio_dev *dev)
 static int orion_mdio_wait_ready(struct mii_bus *bus)
 {
 	struct orion_mdio_dev *dev = bus->priv;
-	int count;
-
-	if (dev->err_interrupt <= 0) {
-		count = 0;
-		while (1) {
-			if (orion_mdio_smi_is_done(dev))
-				break;
-
-			if (count > 100) {
-				dev_err(bus->parent,
-					"Timeout: SMI busy for too long\n");
-				return -ETIMEDOUT;
-			}
-
-			udelay(10);
-			count++;
-		}
-	} else {
-		if (!orion_mdio_smi_is_done(dev)) {
+	unsigned long timeout = usecs_to_jiffies(MVMDIO_SMI_TIMEOUT);
+	unsigned long end = jiffies + timeout;
+	int timedout = 0;
+
+	while (1) {
+	        if (orion_mdio_smi_is_done(dev))
+			return 0;
+	        else if (timedout)
+			break;
+
+	        if (dev->err_interrupt <= 0) {
+			usleep_range(MVMDIO_SMI_POLL_INTERVAL_MIN,
+				     MVMDIO_SMI_POLL_INTERVAL_MAX);
+
+			if (time_is_before_jiffies(end))
+				++timedout;
+	        } else {
+			/* wait_event_timeout does not guarantee a delay of at
+			 * least one whole jiffie, so timeout must be no less
+			 * than two.
+			 */
+			if (timeout < 2)
+				timeout = 2;
 			wait_event_timeout(dev->smi_busy_wait,
-				orion_mdio_smi_is_done(dev),
-				msecs_to_jiffies(100));
-			if (!orion_mdio_smi_is_done(dev))
-				return -ETIMEDOUT;
-		}
+				           orion_mdio_smi_is_done(dev),
+				           timeout);
+
+			++timedout;
+	        }
 	}
 
-	return 0;
+	dev_err(bus->parent, "Timeout: SMI busy for too long\n");
+	return  -ETIMEDOUT;
 }
 
 static int orion_mdio_read(struct mii_bus *bus, int mii_id,
 			   int regnum)
 {
 	struct orion_mdio_dev *dev = bus->priv;
-	int count;
 	u32 val;
 	int ret;
 
 	mutex_lock(&dev->lock);
 
 	ret = orion_mdio_wait_ready(bus);
-	if (ret < 0) {
-		mutex_unlock(&dev->lock);
-		return ret;
-	}
+	if (ret < 0)
+		goto out;
 
 	writel(((mii_id << MVMDIO_SMI_PHY_ADDR_SHIFT) |
 		(regnum << MVMDIO_SMI_PHY_REG_SHIFT)  |
 		MVMDIO_SMI_READ_OPERATION),
 	       dev->regs);
 
-	/* Wait for the value to become available */
-	count = 0;
-	while (1) {
-		val = readl(dev->regs);
-		if (val & MVMDIO_SMI_READ_VALID)
-			break;
-
-		if (count > 100) {
-			dev_err(bus->parent, "Timeout when reading PHY\n");
-			mutex_unlock(&dev->lock);
-			return -ETIMEDOUT;
-		}
+	ret = orion_mdio_wait_ready(bus);
+	if (ret < 0)
+		goto out;
 
-		udelay(10);
-		count++;
+	val = readl(dev->regs);
+	if (!(val & MVMDIO_SMI_READ_VALID)) {
+		dev_err(bus->parent, "SMI bus read not valid\n");
+		ret = -ENODEV;
+		goto out;
 	}
 
+	ret = val & 0xFFFF;
+out:
 	mutex_unlock(&dev->lock);
-
-	return val & 0xFFFF;
+	return ret;
 }
 
 static int orion_mdio_write(struct mii_bus *bus, int mii_id,
@@ -150,10 +154,8 @@ static int orion_mdio_write(struct mii_bus *bus, int mii_id,
 	mutex_lock(&dev->lock);
 
 	ret = orion_mdio_wait_ready(bus);
-	if (ret < 0) {
-		mutex_unlock(&dev->lock);
-		return ret;
-	}
+	if (ret < 0)
+		goto out;
 
 	writel(((mii_id << MVMDIO_SMI_PHY_ADDR_SHIFT) |
 		(regnum << MVMDIO_SMI_PHY_REG_SHIFT)  |
@@ -161,9 +163,9 @@ static int orion_mdio_write(struct mii_bus *bus, int mii_id,
 		(value << MVMDIO_SMI_DATA_SHIFT)),
 	       dev->regs);
 
+out:
 	mutex_unlock(&dev->lock);
-
-	return 0;
+	return ret;
 }
 
 static int orion_mdio_reset(struct mii_bus *bus)