From 39b401dbd3a36f04657afa078d1d25278a26e9c9 Mon Sep 17 00:00:00 2001 From: Deepak SIKRI Date: Wed, 4 Apr 2012 04:33:24 +0000 Subject: [PATCH] stmmac: Replace infinite loops by timeouts in mdio r/w This patch removes the infinite waits from the mdio read and write interfaces. These infinite waits have been replaced by the timeout handling. In case if a time out occurs, an error is returned. Signed-off-by: Deepak Sikri Acked-by: Giuseppe Cavallaro Signed-off-by: David S. Miller --- .../net/ethernet/stmicro/stmmac/stmmac_mdio.c | 32 +++++++++++++++---- 1 file changed, 25 insertions(+), 7 deletions(-) diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_mdio.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_mdio.c index 73195329aa46..83292f4edc6b 100644 --- a/drivers/net/ethernet/stmicro/stmmac/stmmac_mdio.c +++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_mdio.c @@ -34,6 +34,22 @@ #define MII_BUSY 0x00000001 #define MII_WRITE 0x00000002 +static int stmmac_mdio_busy_wait(void __iomem *ioaddr, unsigned int mii_addr) +{ + unsigned long curr; + unsigned long finish = jiffies + 3 * HZ; + + do { + curr = jiffies; + if (readl(ioaddr + mii_addr) & MII_BUSY) + cpu_relax(); + else + return 0; + } while (!time_after_eq(curr, finish)); + + return -EBUSY; +} + /** * stmmac_mdio_read * @bus: points to the mii_bus structure @@ -56,9 +72,13 @@ static int stmmac_mdio_read(struct mii_bus *bus, int phyaddr, int phyreg) ((phyreg << 6) & (0x000007C0))); regValue |= MII_BUSY | ((priv->plat->clk_csr & 7) << 2); - do {} while (((readl(priv->ioaddr + mii_address)) & MII_BUSY) == 1); + if (stmmac_mdio_busy_wait(priv->ioaddr, mii_address)) + return -EBUSY; + writel(regValue, priv->ioaddr + mii_address); - do {} while (((readl(priv->ioaddr + mii_address)) & MII_BUSY) == 1); + + if (stmmac_mdio_busy_wait(priv->ioaddr, mii_address)) + return -EBUSY; /* Read the data from the MII data register */ data = (int)readl(priv->ioaddr + mii_data); @@ -88,18 +108,16 @@ static int stmmac_mdio_write(struct mii_bus *bus, int phyaddr, int phyreg, value |= MII_BUSY | ((priv->plat->clk_csr & 7) << 2); - /* Wait until any existing MII operation is complete */ - do {} while (((readl(priv->ioaddr + mii_address)) & MII_BUSY) == 1); + if (stmmac_mdio_busy_wait(priv->ioaddr, mii_address)) + return -EBUSY; /* Set the MII address register to write */ writel(phydata, priv->ioaddr + mii_data); writel(value, priv->ioaddr + mii_address); /* Wait until any existing MII operation is complete */ - do {} while (((readl(priv->ioaddr + mii_address)) & MII_BUSY) == 1); - - return 0; + return stmmac_mdio_busy_wait(priv->ioaddr, mii_address); } /** -- 2.39.5