[PATCH v2 1/1] mac80211: tear down all agg queues when restart/reconfig hw

[PATCH v2 1/1] mac80211: tear down all agg queues when restart/reconfig hw

[wey-yi.w.guy]

From: Wey-Yi Guy <wey-yi.w.guy@intel.com>

When there is a need to restart/reconfig hw, tear down all the
aggregation queues and let the mac80211 and driver get in-sync and have
the opportunity to re-establish the aggregation queues.

Signed-off-by: Wey-Yi Guy <wey-yi.w.guy@intel.com>
---
v2: add rcu_read_lock()
---
 net/mac80211/util.c |   10 ++++++++++
 1 files changed, 10 insertions(+), 0 deletions(-)

diff --git a/net/mac80211/util.c b/net/mac80211/util.c
index ca170b4..27e8833 100644
--- a/net/mac80211/util.c
+++ b/net/mac80211/util.c
@@ -1188,6 +1188,16 @@ int ieee80211_reconfig(struct ieee80211_local *local)
 	ieee80211_wake_queues_by_reason(hw,
 			IEEE80211_QUEUE_STOP_REASON_SUSPEND);
 
+	rcu_read_lock();
+
+	if (hw->flags & IEEE80211_HW_AMPDU_AGGREGATION) {
+		list_for_each_entry_rcu(sta, &local->sta_list, list) {
+			ieee80211_sta_tear_down_BA_sessions(sta);
+		}
+	}
+
+	rcu_read_unlock();
+
 	/*
 	 * If this is for hw restart things are still running.
 	 * We may want to change that later, however.
-- 
1.5.6.3

Re: [PATCH v2 1/1] mac80211: tear down all agg queues when restart/reconfig hw

[Johannes Berg]

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On Tue, 2010-02-02 at 17:17 -0800, wey-yi.w.guy@intel.com wrote:
> From: Wey-Yi Guy <wey-yi.w.guy@intel.com>
> 
> When there is a need to restart/reconfig hw, tear down all the
> aggregation queues and let the mac80211 and driver get in-sync and have
> the opportunity to re-establish the aggregation queues.
> 
> Signed-off-by: Wey-Yi Guy <wey-yi.w.guy@intel.com>
> ---
> v2: add rcu_read_lock()
> ---
>  net/mac80211/util.c |   10 ++++++++++
>  1 files changed, 10 insertions(+), 0 deletions(-)
> 
> diff --git a/net/mac80211/util.c b/net/mac80211/util.c
> index ca170b4..27e8833 100644
> --- a/net/mac80211/util.c
> +++ b/net/mac80211/util.c
> @@ -1188,6 +1188,16 @@ int ieee80211_reconfig(struct ieee80211_local *local)
>  	ieee80211_wake_queues_by_reason(hw,
>  			IEEE80211_QUEUE_STOP_REASON_SUSPEND);
>  
> +	rcu_read_lock();
> +
> +	if (hw->flags & IEEE80211_HW_AMPDU_AGGREGATION) {
> +		list_for_each_entry_rcu(sta, &local->sta_list, list) {
> +			ieee80211_sta_tear_down_BA_sessions(sta);
> +		}
> +	}
> +
> +	rcu_read_unlock();
> +

I wonder if that shouldn't be _before_ waking up the queues again, since
otherwise we'd enqueue all the frames that might have come in while
reconfiguring as aggregation frames still?

johannes

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Re: [PATCH v2 1/1] mac80211: tear down all agg queues when restart/reconfig hw

[Guy, Wey-Yi]

On Wed, 2010-02-03 at 00:44 -0800, Johannes Berg wrote:
> On Tue, 2010-02-02 at 17:17 -0800, wey-yi.w.guy@intel.com wrote:
> > From: Wey-Yi Guy <wey-yi.w.guy@intel.com>
> > 
> > When there is a need to restart/reconfig hw, tear down all the
> > aggregation queues and let the mac80211 and driver get in-sync and have
> > the opportunity to re-establish the aggregation queues.
> > 
> > Signed-off-by: Wey-Yi Guy <wey-yi.w.guy@intel.com>
> > ---
> > v2: add rcu_read_lock()
> > ---
> >  net/mac80211/util.c |   10 ++++++++++
> >  1 files changed, 10 insertions(+), 0 deletions(-)
> > 
> > diff --git a/net/mac80211/util.c b/net/mac80211/util.c
> > index ca170b4..27e8833 100644
> > --- a/net/mac80211/util.c
> > +++ b/net/mac80211/util.c
> > @@ -1188,6 +1188,16 @@ int ieee80211_reconfig(struct ieee80211_local *local)
> >  	ieee80211_wake_queues_by_reason(hw,
> >  			IEEE80211_QUEUE_STOP_REASON_SUSPEND);
> >  
> > +	rcu_read_lock();
> > +
> > +	if (hw->flags & IEEE80211_HW_AMPDU_AGGREGATION) {
> > +		list_for_each_entry_rcu(sta, &local->sta_list, list) {
> > +			ieee80211_sta_tear_down_BA_sessions(sta);
> > +		}
> > +	}
> > +
> > +	rcu_read_unlock();
> > +
> 
> I wonder if that shouldn't be _before_ waking up the queues again, since
> otherwise we'd enqueue all the frames that might have come in while
> reconfiguring as aggregation frames still?
> 
not sure, the current place works for my test