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>

1 files changed, 6 insertions, 8 deletions

diff --git a/drivers/net/phy/mdio-sun4i.c b/drivers/net/phy/mdio-sun4i.c
index 61d3f4ebf52e..7f25e49ae37f 100644
--- 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);
         }