Re: [PATCH 1/4] mac80211: fix CSA tx queue locking

[Johannes Berg <johannes@sipsolutions.net>]

On Wed, 2014-03-05 at 15:27 +0100, Michal Kazior wrote:

> +void ieee80211_recalc_csa_block_tx(struct ieee80211_local *local)
> +{
> +	lockdep_assert_held(&local->mtx);
> +
> +	if (ieee80211_csa_needs_block_tx(local))
> +		ieee80211_stop_queues_by_reason(&local->hw,
> +					IEEE80211_MAX_QUEUE_MAP,
> +					IEEE80211_QUEUE_STOP_REASON_CSA);
> +	else
> +		ieee80211_wake_queues_by_reason(&local->hw,
> +					IEEE80211_MAX_QUEUE_MAP,
> +					IEEE80211_QUEUE_STOP_REASON_CSA);
> +}

I don't like this function, even if technically stop is idempotent, it
still seems strange to call this "recalc".

> @@ -1092,7 +1131,11 @@ static int ieee80211_stop_ap(struct wiphy *wiphy, struct net_device *dev)
>  	old_probe_resp = sdata_dereference(sdata->u.ap.probe_resp, sdata);
>  
>  	/* abort any running channel switch */
> +	mutex_lock(&local->mtx);
>  	sdata->vif.csa_active = false;
> +	ieee80211_recalc_csa_block_tx(local);
> +	mutex_unlock(&local->mtx);

In fact, here you don't care about the stop queues part at all, afaict.


>  	sdata->csa_chandef = params->chandef;
> +	sdata->csa_block_tx = params->block_tx;

doesn't that more belong to the previous patch?

johannes