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	Mon, 23 Apr 2007 16:53:33 -0400
Date: Mon, 23 Apr 2007 22:53:37 +0200
From: Jiri Benc <jbenc@suse.cz>
To: Michael Wu <flamingice@sourmilk.net>
Cc: linux-wireless@vger.kernel.org,
	John Linville <linville@tuxdriver.com>
Subject: Re: [PATCH 04/13] mac80211: disable tasklets on close
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On Mon, 23 Apr 2007 14:48:13 -0400, Michael Wu wrote:
> This prevents all tasklets from running when the device is down.
> 
> [...]
> --- a/net/mac80211/ieee80211.c
> +++ b/net/mac80211/ieee80211.c
> @@ -2276,7 +2276,6 @@ static int ieee80211_master_open(struct net_device *dev)
>  	list_for_each_entry(sdata, &local->sub_if_list, list) {
>  		if (sdata->dev != dev && netif_running(sdata->dev)) {
>  			res = 0;
> -			tasklet_enable(&local->tx_pending_tasklet);
>  			break;
>  		}
>  	}
> @@ -2289,7 +2288,6 @@ static int ieee80211_master_stop(struct net_device *dev)
>  	struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr);
>  	struct ieee80211_sub_if_data *sdata;
>  
> -	tasklet_disable(&local->tx_pending_tasklet);
>  	read_lock(&local->sub_if_lock);
>  	list_for_each_entry(sdata, &local->sub_if_list, list) {
>  		if (sdata->dev != dev && netif_running(sdata->dev)) {
> @@ -2401,6 +2399,8 @@ static int ieee80211_open(struct net_device *dev)
>  
>  	if (local->open_count == 0) {
>  		res = 0;
> +		tasklet_enable(&local->tx_pending_tasklet);
> +		tasklet_enable(&local->tasklet);
>  		if (local->ops->open)
>  			res = local->ops->open(local_to_hw(local));
>  		if (res == 0) {
> @@ -2475,6 +2475,8 @@ static int ieee80211_stop(struct net_device *dev)
>  			dev_close(local->apdev);
>  		if (local->ops->stop)
>  			local->ops->stop(local_to_hw(local));
> +		tasklet_disable(&local->tx_pending_tasklet);
> +		tasklet_disable(&local->tasklet);


This seems suspicious to me. Will it really work when somebody take the
master interface down by hand while some other interface is still
active?

Thanks,

 Jiri

>  	}
>  	if (local->ops->remove_interface) {
>  		struct ieee80211_if_init_conf conf;
> @@ -4713,6 +4715,8 @@ struct ieee80211_hw *ieee80211_alloc_hw(size_t priv_data_len,
>  	tasklet_init(&local->tasklet,
>  		     ieee80211_tasklet_handler,
>  		     (unsigned long) local);
> +	tasklet_disable(&local->tasklet);
> +
>  	skb_queue_head_init(&local->skb_queue);
>  	skb_queue_head_init(&local->skb_queue_unreliable);
>  
> 


-- 
Jiri Benc
SUSE Labs