On Thu, Sep 11, 2008 at 10:39:37AM -0700, Johannes Berg wrote: > On Thu, 2008-09-11 at 10:33 -0700, Luis R. Rodriguez wrote: > > On Thu, Sep 11, 2008 at 09:53:15AM -0700, Johannes Berg wrote: > > > On Thu, 2008-09-11 at 09:50 -0700, Luis R. Rodriguez wrote: > > > > > I had actually tried > > > > > (http://johannes.sipsolutions.net/patches/kernel/ath9k-sta-node.patch) > > > > Just a comment so far from the patch. > > > > > + rcu_read_unlock(); > > > + > > > + /* the "!an" here is fine even outside RCU lock */ > > > > Why is that? I fail to see that. > > Well take the larger bit of code: > > struct something *an = NULL; > > ... > > rcu_read_lock(); > sta = ieee80211_find_sta(hw, hdr->addr2); > if (sta) > an = (void *) sta->drv_priv; > > if (an) { > ath_rx_input(sc, an, > hw->conf.ht_conf.ht_supported, > skb, status, &st); > } > rcu_read_unlock(); > > /* the "!an" here is fine even outside RCU lock */ > if (!an || (st != ATH_RX_CONSUMED)) > __ieee80211_rx(hw, skb, &rx_status); > > > So at this point it's only checking whether above it had a pointer, it's > not accessing it. Think of the "an" variable, after rcu_read_unlock(), > as a bool indicating whether or not the code that just happened had > access to the node or not. I see now, thanks :) Luis -- To unsubscribe from this list: send the line "unsubscribe linux-wireless" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
