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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>
hifive-unleashed-5.1
Christian Riesch 2012-04-16 04:35:25 +00:00 committed by David S. Miller
parent cda31e10ba
commit 5b76d0600b
1 changed files with 5 additions and 0 deletions

View File

@ -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;
}