From: Dimitris Michailidis <dm@chelsio.com>
To: Gavin Shan <shangw@linux.vnet.ibm.com>, netdev@vger.kernel.org
Subject: Re: [PATCH 2/2] net/cxgb4: Don't retrieve stats during recovery
Date: Mon, 20 Jan 2014 14:05:18 -0800 [thread overview]
Message-ID: <52DD9D9E.3010205@chelsio.com> (raw)
In-Reply-To: <1390187144-15495-2-git-send-email-shangw@linux.vnet.ibm.com>
On 01/19/2014 07:05 PM, Gavin Shan wrote:
> We possiblly retrieve the adapter's statistics during EEH recovery
> and that should be disallowed. Otherwise, it would possibly incur
> replicate EEH error and EEH recovery is going to fail eventually.
> The patch checks if the PCI device is off-line before statistic
> retrieval.
The net_devices are detached during EEH so I think netif_device_present
is a better check than pci_channel_offline. I am not sure such a test
should be left to each driver though. If you do end up putting it in
the driver it needs better synchronization with the EEH handlers as Ben
mentioned.
>
> Signed-off-by: Gavin Shan <shangw@linux.vnet.ibm.com>
> ---
> drivers/net/ethernet/chelsio/cxgb4/cxgb4_main.c | 11 +++++++++++
> 1 file changed, 11 insertions(+)
>
> diff --git a/drivers/net/ethernet/chelsio/cxgb4/cxgb4_main.c b/drivers/net/ethernet/chelsio/cxgb4/cxgb4_main.c
> index c8eafbf..b0e72fb 100644
> --- a/drivers/net/ethernet/chelsio/cxgb4/cxgb4_main.c
> +++ b/drivers/net/ethernet/chelsio/cxgb4/cxgb4_main.c
> @@ -4288,6 +4288,17 @@ static struct rtnl_link_stats64 *cxgb_get_stats(struct net_device *dev,
> struct port_info *p = netdev_priv(dev);
> struct adapter *adapter = p->adapter;
>
> + /*
> + * We possibly retrieve the statistics while the PCI
> + * device is off-line. That would cause the recovery
> + * on off-lined PCI device going to fail. So it's
> + * reasonable to block it during the recovery period.
> + */
> + if (pci_channel_offline(adapter->pdev)) {
> + memset(ns, 0, sizeof(*ns));
> + return ns;
> + }
> +
> spin_lock(&adapter->stats_lock);
> t4_get_port_stats(adapter, p->tx_chan, &stats);
> spin_unlock(&adapter->stats_lock);
>
next prev parent reply other threads:[~2014-01-20 23:00 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-01-20 3:05 [PATCH 1/2] net/cxgb4: Avoid disabling PCI device for towice Gavin Shan
2014-01-20 3:05 ` [PATCH 2/2] net/cxgb4: Don't retrieve stats during recovery Gavin Shan
2014-01-20 3:49 ` Ben Hutchings
2014-01-20 14:35 ` Sergei Shtylyov
2014-01-20 22:05 ` Dimitris Michailidis [this message]
[not found] ` <20140121023404.GA6575@shangw.(null)>
[not found] ` <20140123013134.GA5947@shangw.(null)>
2014-01-23 2:17 ` Dimitrios Michailidis
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