From 54472edff0afa09e35828b2b81b00695a9da1c17 Mon Sep 17 00:00:00 2001 From: Sekhar Nori Date: Wed, 9 May 2018 21:15:15 +0530 Subject: [PATCH] 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 Signed-off-by: Sekhar Nori Reviewed-by: Grygorii Strashko Signed-off-by: David S. Miller --- drivers/net/ethernet/ti/davinci_mdio.c | 15 ++++++++------- 1 file changed, 8 insertions(+), 7 deletions(-) diff --git a/drivers/net/ethernet/ti/davinci_mdio.c b/drivers/net/ethernet/ti/davinci_mdio.c index 3c33f45..98a1c97f 100644 --- a/drivers/net/ethernet/ti/davinci_mdio.c +++ b/drivers/net/ethernet/ti/davinci_mdio.c @@ -34,6 +34,7 @@ #include #include #include +#include #include #include #include @@ -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(®s->control) & CONTROL_IDLE) - return 0; - } - dev_err(data->dev, "timed out waiting for idle\n"); - return -ETIMEDOUT; + ret = readl_poll_timeout(®s->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) -- 2.7.4