From 5b76d0600b2b08eef77f8e9226938b7b6bde3099 Mon Sep 17 00:00:00 2001 From: Christian Riesch <christian.riesch@omicron.at> Date: Mon, 16 Apr 2012 04:35:25 +0000 Subject: [PATCH] davinci_mdio: Fix MDIO timeout check Under heavy load (flood ping) it is possible for the MDIO timeout to expire before the loop checks the GO bit again. This patch adds an additional check whether the operation was done before actually returning -ETIMEDOUT. To reproduce this bug, flood ping the device, e.g., ping -f -l 1000 After some time, a "timed out waiting for user access" warning may appear. And even worse, link may go down since the PHY reported a timeout. Signed-off-by: Christian Riesch <christian.riesch@omicron.at> Cc: <stable@vger.kernel.org> Cc: Cyril Chemparathy <cyril@ti.com> Signed-off-by: David S. Miller <davem@davemloft.net> --- drivers/net/ethernet/ti/davinci_mdio.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/drivers/net/ethernet/ti/davinci_mdio.c b/drivers/net/ethernet/ti/davinci_mdio.c index 2757c7d6e633..e4e47088e26b 100644 --- a/drivers/net/ethernet/ti/davinci_mdio.c +++ b/drivers/net/ethernet/ti/davinci_mdio.c @@ -181,6 +181,11 @@ static inline int wait_for_user_access(struct davinci_mdio_data *data) __davinci_mdio_reset(data); return -EAGAIN; } + + reg = __raw_readl(®s->user[0].access); + if ((reg & USERACCESS_GO) == 0) + return 0; + dev_err(data->dev, "timed out waiting for user access\n"); return -ETIMEDOUT; } -- 2.20.1