On Wed, Aug 21, 2013 at 11:35 PM, Johannes Berg <johannes@xxxxxxxxxxxxxxxx> wrote: > From: Johannes Berg <johannes.berg@xxxxxxxxx> > > If it is needed to disconnect multiple virtual interfaces after > (WoWLAN-) suspend, the most obvious approach would be to iterate > all interfaces by calling ieee80211_iterate_active_interfaces() > and then call ieee80211_resume_disconnect() for each one. This > is what the iwlmvm driver does. > > Unfortunately, this causes a locking dependency from mac80211's > iflist_mtx to the key_mtx. This is problematic as the former is > intentionally never held while calling any driver operation to > allow drivers to iterate with their own locks held. The key_mtx > is held while installing a key into the driver though, so this > new lock dependency means drivers implementing the logic above > can no longer hold their own lock while iterating. > > To fix this, modify the ieee80211_resume_disconnect() API to do > the iteration in there (using RCU) while holding the key_mtx so > there's no new lock dependency, and let the driver device which > interface should be disconnected by passing a decision function > that returns true/false. > can't you simply add a new rtnl-locked interface iterator? Eliad. -- 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
