ENGR00137130 Fec: Can't bootup from NFS when eth0 and eth1 all linkedrel_imx_2.6.35_10.12.01_RC3

This reverts commit d4b2153e87aa2d35b5f830744c14a04e386b3adb.
"fec: use interrupt for MDIO completion indication"

In IMX28, eth0 and eth1 shared MDIO, using interrupt to indicate
mdio read or write complete makes eth1 not working.

since mdio_read() can only access eth0 reg space, getting/setting eth1
phy state by writing management frame to eth0 reg space, will trigger eth1
mdio complete indication interrupt. But eth1 EIR register will not updated.

Signed-off-by: Zeng Zhaoming <b32542@freescale.com>

1 files changed, 31 insertions, 24 deletions

diff --git a/drivers/net/fec.c b/drivers/net/fec.c
index d0e2e690b66e..c49e64e8abcc 100644
--- a/drivers/net/fec.c
+++ b/drivers/net/fec.c
@@ -119,10 +119,10 @@
 #define FEC_ENET_TS_TIMER	((uint)0x00008000)
 
 #if defined(CONFIG_FEC_1588) && defined(CONFIG_ARCH_MX28)
-#define FEC_DEFAULT_IMASK (FEC_ENET_TXF | FEC_ENET_RXF | FEC_ENET_MII | \
+#define FEC_DEFAULT_IMASK (FEC_ENET_TXF | FEC_ENET_RXF | \
 				FEC_ENET_TS_AVAIL | FEC_ENET_TS_TIMER)
 #else
-#define FEC_DEFAULT_IMASK (FEC_ENET_TXF | FEC_ENET_RXF | FEC_ENET_MII)
+#define FEC_DEFAULT_IMASK (FEC_ENET_TXF | FEC_ENET_RXF)
 #endif
 
 /* The FEC stores dest/src/type, data, and checksum for receive packets.
@@ -195,7 +195,6 @@ struct fec_enet_private {
 	int	index;
 	int	link;
 	int	full_duplex;
-	struct  completion mdio_done;
 
 	struct	fec_ptp_private *ptp_priv;
 	uint	ptimer_present;
@@ -223,7 +222,7 @@ static void fec_stop(struct net_device *dev);
 #define FEC_MMFR_TA		(2 << 16)
 #define FEC_MMFR_DATA(v)	(v & 0xffff)
 
-#define FEC_MII_TIMEOUT		1000
+#define FEC_MII_TIMEOUT		10000
 
 /* Transmitter timeout */
 #define TX_TIMEOUT (2 * HZ)
@@ -390,10 +389,6 @@ fec_enet_interrupt(int irq, void * dev_id)
 				fpp->prtc++;
 		}
 
-		if (int_events & FEC_ENET_MII) {
-			ret = IRQ_HANDLED;
-			complete(&fep->mdio_done);
-		}
 	} while (int_events);
 
 	return ret;
@@ -710,13 +705,18 @@ spin_unlock:
 		phy_print_status(phy_dev);
 }
 
+/*
+ * NOTE: a MII transaction is during around 25 us, so polling it...
+ */
 static int fec_enet_mdio_read(struct mii_bus *bus, int mii_id, int regnum)
 {
 	struct fec_enet_private *fep = bus->priv;
-	unsigned long time_left;
+	int timeout = FEC_MII_TIMEOUT;
 
 	fep->mii_timeout = 0;
-	init_completion(&fep->mdio_done);
+
+	/* clear MII end of transfer bit*/
+	writel(FEC_ENET_MII, fep->hwp + FEC_IEVENT);
 
 	/* start a read op */
 	writel(FEC_MMFR_ST | FEC_MMFR_OP_READ |
@@ -724,12 +724,13 @@ static int fec_enet_mdio_read(struct mii_bus *bus, int mii_id, int regnum)
 		FEC_MMFR_TA, fep->hwp + FEC_MII_DATA);
 
 	/* wait for end of transfer */
-	time_left = wait_for_completion_timeout(&fep->mdio_done,
-		usecs_to_jiffies(FEC_MII_TIMEOUT));
-	if (time_left == 0) {
-		fep->mii_timeout = 1;
-		printk(KERN_ERR "FEC: MDIO read timeout\n");
-		return -ETIMEDOUT;
+	while (!(readl(fep->hwp + FEC_IEVENT) & FEC_ENET_MII)) {
+		cpu_relax();
+		if (timeout-- < 0) {
+			fep->mii_timeout = 1;
+			printk(KERN_ERR "FEC: MDIO read timeout\n");
+			return -ETIMEDOUT;
+		}
 	}
 	/* return value */
 	return FEC_MMFR_DATA(readl(fep->hwp + FEC_MII_DATA));
@@ -739,10 +740,12 @@ static int fec_enet_mdio_write(struct mii_bus *bus, int mii_id, int regnum,
 			   u16 value)
 {
 	struct fec_enet_private *fep = bus->priv;
-	unsigned long time_left;
+	int timeout = FEC_MII_TIMEOUT;
 
 	fep->mii_timeout = 0;
-	init_completion(&fep->mdio_done);
+
+	/* clear MII end of transfer bit*/
+	writel(FEC_ENET_MII, fep->hwp + FEC_IEVENT);
 
 	/* start a write op */
 	writel(FEC_MMFR_ST | FEC_MMFR_OP_WRITE |
@@ -751,12 +754,13 @@ static int fec_enet_mdio_write(struct mii_bus *bus, int mii_id, int regnum,
 		fep->hwp + FEC_MII_DATA);
 
 	/* wait for end of transfer */
-	time_left = wait_for_completion_timeout(&fep->mdio_done,
-		usecs_to_jiffies(FEC_MII_TIMEOUT));
-	if (time_left == 0) {
-		fep->mii_timeout = 1;
-		printk(KERN_ERR "FEC: MDIO write timeout\n");
-		return -ETIMEDOUT;
+	while (!(readl(fep->hwp + FEC_IEVENT) & FEC_ENET_MII)) {
+		cpu_relax();
+		if (timeout-- < 0) {
+			fep->mii_timeout = 1;
+			printk(KERN_ERR "FEC: MDIO write timeout\n");
+			return -ETIMEDOUT;
+		}
 	}
 
 	return 0;
@@ -1409,6 +1413,9 @@ fec_stop(struct net_device *dev)
 	writel(1, fep->hwp + FEC_ECNTRL);
 	udelay(10);
 
+	/* Clear outstanding MII command interrupts. */
+	writel(FEC_ENET_MII, fep->hwp + FEC_IEVENT);
+
 #ifdef CONFIG_ARCH_MXS
 	/* Check MII or RMII */
 	if (fep->phy_interface == PHY_INTERFACE_MODE_RMII)