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authorSekhar Nori <nsekhar@ti.com>2018-05-09 21:15:15 +0530
committerDavid S. Miller <davem@davemloft.net>2018-05-10 16:18:59 -0400
commit54472edff0afa09e35828b2b81b00695a9da1c17 (patch)
treedb4fdaf085508718242139a458c75d790cbb15c6 /drivers/net/ethernet/ti
parentbfe1e616b3cdf1176a8f18ca26606ff00785a8de (diff)
drivers: net: davinci_mdio: prevent spurious timeout
A well timed kernel preemption in the time_after() loop in wait_for_idle() can result in a spurious timeout error to be returned. Fix it by using readl_poll_timeout() which takes care of this issue. Reviewed-by: Andrew Lunn <andrew@lunn.ch> Signed-off-by: Sekhar Nori <nsekhar@ti.com> Reviewed-by: Grygorii Strashko <grygorii.strashko@ti.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'drivers/net/ethernet/ti')
-rw-r--r--drivers/net/ethernet/ti/davinci_mdio.c15
1 files changed, 8 insertions, 7 deletions
diff --git a/drivers/net/ethernet/ti/davinci_mdio.c b/drivers/net/ethernet/ti/davinci_mdio.c
index 3c33f4504d8e..98a1c97fb95e 100644
--- a/drivers/net/ethernet/ti/davinci_mdio.c
+++ b/drivers/net/ethernet/ti/davinci_mdio.c
@@ -34,6 +34,7 @@
#include <linux/clk.h>
#include <linux/err.h>
#include <linux/io.h>
+#include <linux/iopoll.h>
#include <linux/pm_runtime.h>
#include <linux/davinci_emac.h>
#include <linux/of.h>
@@ -227,14 +228,14 @@ static inline int wait_for_user_access(struct davinci_mdio_data *data)
static inline int wait_for_idle(struct davinci_mdio_data *data)
{
struct davinci_mdio_regs __iomem *regs = data->regs;
- unsigned long timeout = jiffies + msecs_to_jiffies(MDIO_TIMEOUT);
+ u32 val, ret;
- while (time_after(timeout, jiffies)) {
- if (__raw_readl(&regs->control) & CONTROL_IDLE)
- return 0;
- }
- dev_err(data->dev, "timed out waiting for idle\n");
- return -ETIMEDOUT;
+ ret = readl_poll_timeout(&regs->control, val, val & CONTROL_IDLE,
+ 0, MDIO_TIMEOUT * 1000);
+ if (ret)
+ dev_err(data->dev, "timed out waiting for idle\n");
+
+ return ret;
}
static int davinci_mdio_read(struct mii_bus *bus, int phy_id, int phy_reg)