net: sun4i: fix timeout check

The current timeout check is comparing two constant values, so it won't
ever detect a timeout. This patch reworks the affected code a bit so it
has a chance at detecting timeouts correctly.

Signed-off-by: Emilio López <emilio@elopez.com.ar>
Acked-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/phy/mdio-sun4i.c b/drivers/net/phy/mdio-sun4i.c
index 61d3f4e..7f25e49 100644 (file)
--- a/drivers/net/phy/mdio-sun4i.c
+++ b/drivers/net/phy/mdio-sun4i.c
@@ -40,7 +40,7 @@ struct sun4i_mdio_data {
 static int sun4i_mdio_read(struct mii_bus *bus, int mii_id, int regnum)
 {
        struct sun4i_mdio_data *data = bus->priv;
-       unsigned long start_jiffies;
+       unsigned long timeout_jiffies;
        int value;
 
        /* issue the phy address and reg */
@@ -49,10 +49,9 @@ static int sun4i_mdio_read(struct mii_bus *bus, int mii_id, int regnum)
        writel(0x1, data->membase + EMAC_MAC_MCMD_REG);
 
        /* Wait read complete */
-       start_jiffies = jiffies;
+       timeout_jiffies = jiffies + MDIO_TIMEOUT;
        while (readl(data->membase + EMAC_MAC_MIND_REG) & 0x1) {
-               if (time_after(start_jiffies,
-                              start_jiffies + MDIO_TIMEOUT))
+               if (time_is_before_jiffies(timeout_jiffies))
                        return -ETIMEDOUT;
                msleep(1);
        }
@@ -69,7 +68,7 @@ static int sun4i_mdio_write(struct mii_bus *bus, int mii_id, int regnum,
                            u16 value)
 {
        struct sun4i_mdio_data *data = bus->priv;
-       unsigned long start_jiffies;
+       unsigned long timeout_jiffies;
 
        /* issue the phy address and reg */
        writel((mii_id << 8) | regnum, data->membase + EMAC_MAC_MADR_REG);
@@ -77,10 +76,9 @@ static int sun4i_mdio_write(struct mii_bus *bus, int mii_id, int regnum,
        writel(0x1, data->membase + EMAC_MAC_MCMD_REG);
 
        /* Wait read complete */
-       start_jiffies = jiffies;
+       timeout_jiffies = jiffies + MDIO_TIMEOUT;
        while (readl(data->membase + EMAC_MAC_MIND_REG) & 0x1) {
-               if (time_after(start_jiffies,
-                              start_jiffies + MDIO_TIMEOUT))
+               if (time_is_before_jiffies(timeout_jiffies))
                        return -ETIMEDOUT;
                msleep(1);
        }