Subject: Re: [PATCH] sky2: Lock transmit queue while disabling device

From: Michael Breuer <[email-masked]>
Date: Thu, 31 Dec 2009 10:58:15 -0500

This doesn't solve the issue on my system. Just ran a test - same 
errors. I don't think that the under-load errors I'm seeing involve 
sky2_detatch. I'm thinking it's related to the dhcp AF_INTERNET fix that 
solved the lockup under load - that something outside of sky2 is 
corrupting an skb.
On 12/31/2009 5:55 AM, Mike McCormack wrote:
> netif_device_detach() does not take the tx_lock, so it's
>   possible that a call to sky2_xmit_frame is still in
>   progress after netif_device_detach() is complete.
>
> Take netif_tx_lock() to make sure all transmits have
>   stopped while we're disabling the devices and that
>   no other CPU is still transmitting a frame after
>   we've disabling the device.
>
> Proposed fix for "sky2 panic under load" reported by Berck E. Nash.
>
> Signed-off-by: Mike McCormack<[email-masked]>
> ---
>   drivers/net/sky2.c |    2 ++
>   1 files changed, 2 insertions(+), 0 deletions(-)
>
> diff --git a/drivers/net/sky2.c b/drivers/net/sky2.c
> index faa4841..8ae8520 100644
> --- a/drivers/net/sky2.c
> +++ b/drivers/net/sky2.c
> @@ -3176,7 +3176,9 @@ static void sky2_reset(struct sky2_hw *hw)
>   static void sky2_detach(struct net_device *dev)
>   {
>   	if (netif_running(dev)) {
> +		netif_tx_lock(dev);
>   		netif_device_detach(dev);	/* stop txq */
> +		netif_tx_unlock(dev);
>   		sky2_down(dev);
>   	}
>   }
>