Re: regression: tethering fails in 3.5 with iwlwifi

[Eric Dumazet <eric.dumazet@gmail.com>]

On Thu, 2012-09-20 at 16:22 +0300, Artem Bityutskiy wrote:

> 
> OK, I've tried almost this (see below) and it solves my issue:
> 
> diff --git a/net/mac80211/rx.c b/net/mac80211/rx.c
> index 965e6ec..7f079d0 100644
> --- a/net/mac80211/rx.c
> +++ b/net/mac80211/rx.c
> @@ -1798,9 +1798,13 @@ ieee80211_deliver_skb(struct ieee80211_rx_data *rx)
>  
>                 if (skb) {
>                         /* deliver to local stack */
> -                       skb->protocol = eth_type_trans(skb, dev);
> -                       memset(skb->cb, 0, sizeof(skb->cb));
> -                       netif_receive_skb(skb);
> +                       if (pskb_may_pull(skb, 40)) {
> +                               skb->protocol = eth_type_trans(skb, dev);
> +                               memset(skb->cb, 0, sizeof(skb->cb));
> +                               netif_receive_skb(skb);
> +                       } else {
> +                               kfree_skb(skb);
> +                       }
>                 }
>         }
> 

OK but you cant do that, or small frames will be dropped.

Anyway its a hack, we should find the buggy layer.

You could use dropwatch (drop_monitor) to check where frame is dropped.

modprobe drop_monitor
dropwatch -l kas