netdev - [PATCH] net: sun4i: fix timeout check

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Message-Id: <1374541758-2025-1-git-send-email-emilio@elopez.com.ar>
Date:	Mon, 22 Jul 2013 22:09:18 -0300
From:	Emilio López <emilio@...pez.com.ar>
To:	Maxime Ripard <maxime.ripard@...e-electrons.com>,
	davem@...emloft.net
Cc:	netdev@...r.kernel.org,
	Emilio López <emilio@...pez.com.ar>
Subject: [PATCH] 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@...pez.com.ar>
---
 drivers/net/phy/mdio-sun4i.c | 14 ++++++--------
 1 file changed, 6 insertions(+), 8 deletions(-)

diff --git a/drivers/net/phy/mdio-sun4i.c b/drivers/net/phy/mdio-sun4i.c
index 61d3f4e..7f25e49 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);
 	}
-- 
1.8.3.3

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