mac80211: fix spurious RCU warning and update documentation
Document rx vs tx status concurrency requirements.
Signed-off-by: Felix Fietkau <nbd@openwrt.org>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
diff --git a/net/mac80211/rate.c b/net/mac80211/rate.c
index 0d51877..d3f414f 100644
--- a/net/mac80211/rate.c
+++ b/net/mac80211/rate.c
@@ -688,8 +688,15 @@
struct ieee80211_sta *pubsta,
struct ieee80211_sta_rates *rates)
{
- struct ieee80211_sta_rates *old = rcu_dereference(pubsta->rates);
+ struct ieee80211_sta_rates *old;
+ /*
+ * mac80211 guarantees that this function will not be called
+ * concurrently, so the following RCU access is safe, even without
+ * extra locking. This can not be checked easily, so we just set
+ * the condition to true.
+ */
+ old = rcu_dereference_protected(pubsta->rates, true);
rcu_assign_pointer(pubsta->rates, rates);
if (old)
kfree_rcu(old, rcu_head);