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mlxsw: core: Fix race condition in __mlxsw_emad_transmit

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Under certain conditions EMAD responses can be returned from the device
even before setting trans_active. This will cause the EMAD Rx listener
to drop the EMAD response - as there are no active transactions - and
timeouts will be generated.

Fix this by setting trans_active before transmitting the EMAD skb.

Fixes: 4ec14b7634 ("mlxsw: Add interface to access registers and process events")
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Ido Schimmel 2015-10-15 08:21:55 +02:00 committed by David S. Miller
parent dde4b5ae65
commit 53ca376eec
1 changed files with 9 additions and 4 deletions
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13
drivers/net/ethernet/mellanox/mlxsw/core.c
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@ -374,26 +374,31 @@ static int __mlxsw_emad_transmit(struct mlxsw_core *mlxsw_core,
int err;
int ret;
mlxsw_core->emad.trans_active = true;
err = mlxsw_core_skb_transmit(mlxsw_core->driver_priv, skb, tx_info);
if (err) {
dev_err(mlxsw_core->bus_info->dev, "Failed to transmit EMAD (tid=%llx)\n",
mlxsw_core->emad.tid);
dev_kfree_skb(skb);
return err;
goto trans_inactive_out;
}
mlxsw_core->emad.trans_active = true;
ret = wait_event_timeout(mlxsw_core->emad.wait,
!(mlxsw_core->emad.trans_active),
msecs_to_jiffies(MLXSW_EMAD_TIMEOUT_MS));
if (!ret) {
dev_warn(mlxsw_core->bus_info->dev, "EMAD timed-out (tid=%llx)\n",
mlxsw_core->emad.tid);
mlxsw_core->emad.trans_active = false;
return -EIO;
err = -EIO;
goto trans_inactive_out;
}
return 0;
trans_inactive_out:
mlxsw_core->emad.trans_active = false;
return err;
}
static int mlxsw_emad_process_status(struct mlxsw_core *mlxsw_core,