Re: [PATCH] mac80211: Deny new BA agreements from being started during offchannel operation

[Johannes Berg <johannes@sipsolutions.net>]

On Wed, 2010-10-06 at 12:12 -0700, Luis R. Rodriguez wrote:

> Good question, will ieee80211_offchannel_ps_disable() possibly be
> called during suspend? I can imagine its possible. So how about we
> check for local->quiescing prior to lifting the flag only:

Or suspended? I'm not really sure .. this will probably interact badly
anyway. Hmm.

johannes

> From 374cbccafadc22ba261dd3bc5f68758106872448 Mon Sep 17 00:00:00 2001
> From: Luis R. Rodriguez <lrodriguez@atheros.com>
> Date: Tue, 21 Sep 2010 15:27:02 -0400
> Subject: [PATCH v3] mac80211: Deny new BA agreements from being started during offchannel operation
> 
> It only makes sense to allow BA agreements when we are going to
> spend some time on the operating channel. This blocks all new
> incoming ADDBA requests while we go offchannel, but keeps
> existing BA agreements alive.
> 
> Cc: srinivasa.duvvuri@atheros.com
> Cc: matt.smith@atheros.com
> Cc: bennyam.malavazi@atheros.com
> Signed-off-by: Luis R. Rodriguez <lrodriguez@atheros.com>
> ---
>  net/mac80211/agg-rx.c     |    8 ++++++--
>  net/mac80211/offchannel.c |   17 +++++++++++++++++
>  net/mac80211/sta_info.h   |    3 ++-
>  3 files changed, 25 insertions(+), 3 deletions(-)
> 
> diff --git a/net/mac80211/agg-rx.c b/net/mac80211/agg-rx.c
> index 720b7a8..a21d120 100644
> --- a/net/mac80211/agg-rx.c
> +++ b/net/mac80211/agg-rx.c
> @@ -209,8 +209,12 @@ void ieee80211_process_addba_request(struct ieee80211_local *local,
>  
>  	if (test_sta_flags(sta, WLAN_STA_BLOCK_BA)) {
>  #ifdef CONFIG_MAC80211_HT_DEBUG
> -		printk(KERN_DEBUG "Suspend in progress. "
> -		       "Denying ADDBA request\n");
> +		if (local->quiescing)
> +			printk(KERN_DEBUG "Suspend in progress. "
> +			      "Denying ADDBA request\n");
> +		else
> +			printk(KERN_DEBUG "Offchannel operation in progress, "
> +			      "Denying ADDBA request\n");
>  #endif
>  		goto end_no_lock;
>  	}
> diff --git a/net/mac80211/offchannel.c b/net/mac80211/offchannel.c
> index 4b56409..86e9b8d 100644
> --- a/net/mac80211/offchannel.c
> +++ b/net/mac80211/offchannel.c
> @@ -34,6 +34,14 @@ static void ieee80211_offchannel_ps_enable(struct ieee80211_sub_if_data *sdata)
>  
>  	cancel_work_sync(&local->dynamic_ps_enable_work);
>  
> +	if (local->hw.flags & IEEE80211_HW_AMPDU_AGGREGATION) {
> +		struct sta_info *sta;
> +		mutex_lock(&local->sta_mtx);
> +		list_for_each_entry(sta, &local->sta_list, list)
> +			set_sta_flags(sta, WLAN_STA_BLOCK_BA);
> +		mutex_unlock(&local->sta_mtx);
> +	}
> +
>  	if (local->hw.conf.flags & IEEE80211_CONF_PS) {
>  		local->offchannel_ps_enabled = true;
>  		local->hw.conf.flags &= ~IEEE80211_CONF_PS;
> @@ -92,6 +100,15 @@ static void ieee80211_offchannel_ps_disable(struct ieee80211_sub_if_data *sdata)
>  
>  	ieee80211_sta_reset_beacon_monitor(sdata);
>  	ieee80211_sta_reset_conn_monitor(sdata);
> +
> +	if (local->hw.flags & IEEE80211_HW_AMPDU_AGGREGATION &&
> +	    !local->quiescing) {
> +		struct sta_info *sta;
> +		mutex_lock(&local->sta_mtx);
> +		list_for_each_entry(sta, &local->sta_list, list)
> +			clear_sta_flags(sta, WLAN_STA_BLOCK_BA);
> +		mutex_unlock(&local->sta_mtx);
> +	}
>  }
>  
>  void ieee80211_offchannel_stop_beaconing(struct ieee80211_local *local)
> diff --git a/net/mac80211/sta_info.h b/net/mac80211/sta_info.h
> index cf21a2e..2439156 100644
> --- a/net/mac80211/sta_info.h
> +++ b/net/mac80211/sta_info.h
> @@ -36,7 +36,8 @@
>   *	frame to this station is transmitted.
>   * @WLAN_STA_MFP: Management frame protection is used with this STA.
>   * @WLAN_STA_BLOCK_BA: Used to deny ADDBA requests (both TX and RX)
> - *	during suspend/resume and station removal.
> + *	during suspend/resume, station removal, and when we go offchannel
> + *	when associated.
>   * @WLAN_STA_PS_DRIVER: driver requires keeping this station in
>   *	power-save mode logically to flush frames that might still
>   *	be in the queues