mac80211: extend/document powersave API

This modifies hardware flags for powersave to support three different
flags:
 * IEEE80211_HW_SUPPORTS_PS - indicates general PS support
 * IEEE80211_HW_PS_NULLFUNC_STACK - indicates nullfunc sending in software
 * IEEE80211_HW_SUPPORTS_DYNAMIC_PS - indicates dynamic PS on the device

It also adds documentation for all this which explains how to set the
various flags.

Additionally, it fixes a few things:
 * a spot where && was used to test flags
 * enable CONF_PS only when associated again

Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 1 insertions, 1 deletions

diff --git a/net/mac80211/tx.c b/net/mac80211/tx.c
index b18a72690119..cd6bc87eec73 100644
--- a/net/mac80211/tx.c
+++ b/net/mac80211/tx.c
@@ -1295,7 +1295,7 @@ int ieee80211_master_start_xmit(struct sk_buff *skb, struct net_device *dev)
                 return 0;
         }
 
-        if (!(local->hw.flags & IEEE80211_HW_NO_STACK_DYNAMIC_PS) &&
+        if ((local->hw.flags & IEEE80211_HW_PS_NULLFUNC_STACK) &&
             local->hw.conf.dynamic_ps_timeout > 0) {
                 if (local->hw.conf.flags & IEEE80211_CONF_PS) {
                         ieee80211_stop_queues_by_reason(&local->hw,