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authorChristian Riesch <christian.riesch@omicron.at>2012-04-16 04:35:25 +0000
committerDavid S. Miller <davem@davemloft.net>2012-04-17 22:31:59 -0400
commit5b76d0600b2b08eef77f8e9226938b7b6bde3099 (patch)
treee30784093458a10899489d2cced27eb3641074dd
parentcda31e10baf47a8a7d9360d9488fb76294be1ca3 (diff)
downloadxen-5b76d0600b2b08eef77f8e9226938b7b6bde3099.tar.gz
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>
-rw-r--r--drivers/net/ethernet/ti/davinci_mdio.c5
1 files changed, 5 insertions, 0 deletions
diff --git a/drivers/net/ethernet/ti/davinci_mdio.c b/drivers/net/ethernet/ti/davinci_mdio.c
index 2757c7d6e6330..e4e47088e26b9 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(&regs->user[0].access);
+ if ((reg & USERACCESS_GO) == 0)
+ return 0;
+
dev_err(data->dev, "timed out waiting for user access\n");
return -ETIMEDOUT;
}