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, 15 insertions, 16 deletions

diff --git a/net/mac80211/mlme.c b/net/mac80211/mlme.c
index 7709e7645671..a1e683e305f0 100644
--- a/net/mac80211/mlme.c
+++ b/net/mac80211/mlme.c
@@ -775,17 +775,17 @@ static void ieee80211_set_associated(struct ieee80211_sub_if_data *sdata,
         bss_info_changed |= BSS_CHANGED_BASIC_RATES;
         ieee80211_bss_info_change_notify(sdata, bss_info_changed);
 
-        if (local->powersave &&
-                        !(local->hw.flags & IEEE80211_HW_NO_STACK_DYNAMIC_PS)) {
-                if (local->hw.conf.dynamic_ps_timeout > 0)
+        if (local->powersave) {
+                if (!(local->hw.flags & IEEE80211_HW_SUPPORTS_DYNAMIC_PS) &&
+                    local->hw.conf.dynamic_ps_timeout > 0) {
                         mod_timer(&local->dynamic_ps_timer, jiffies +
                                   msecs_to_jiffies(
                                         local->hw.conf.dynamic_ps_timeout));
-                else {
-                        ieee80211_send_nullfunc(local, sdata, 1);
+                } else {
+                        if (local->hw.flags & IEEE80211_HW_PS_NULLFUNC_STACK)
+                                ieee80211_send_nullfunc(local, sdata, 1);
                         conf->flags |= IEEE80211_CONF_PS;
-                        ieee80211_hw_config(local,
-                                            IEEE80211_CONF_CHANGE_PS);
+                        ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_PS);
                 }
         }
 
@@ -1779,16 +1779,14 @@ static void ieee80211_rx_mgmt_beacon(struct ieee80211_sub_if_data *sdata,
         ieee80211_sta_wmm_params(local, ifsta, elems.wmm_param,
                                  elems.wmm_param_len);
 
-        if (!(local->hw.flags & IEEE80211_HW_NO_STACK_DYNAMIC_PS)) {
+        if (local->hw.flags & IEEE80211_HW_PS_NULLFUNC_STACK &&
+            local->hw.conf.flags & IEEE80211_CONF_PS) {
                 directed_tim = check_tim(&elems, ifsta->aid, &is_mc);
 
                 if (directed_tim || is_mc) {
-                        if (local->hw.conf.flags && IEEE80211_CONF_PS) {
-                                local->hw.conf.flags &= ~IEEE80211_CONF_PS;
-                                ieee80211_hw_config(local,
-                                                IEEE80211_CONF_CHANGE_PS);
-                                ieee80211_send_nullfunc(local, sdata, 0);
-                        }
+                        local->hw.conf.flags &= ~IEEE80211_CONF_PS;
+                        ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_PS);
+                        ieee80211_send_nullfunc(local, sdata, 0);
                 }
         }
 
@@ -2694,9 +2692,10 @@ void ieee80211_dynamic_ps_enable_work(struct work_struct *work)
         if (local->hw.conf.flags & IEEE80211_CONF_PS)
                 return;
 
-        ieee80211_send_nullfunc(local, sdata, 1);
-        local->hw.conf.flags |= IEEE80211_CONF_PS;
+        if (local->hw.flags & IEEE80211_HW_PS_NULLFUNC_STACK)
+                ieee80211_send_nullfunc(local, sdata, 1);
 
+        local->hw.conf.flags |= IEEE80211_CONF_PS;
         ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_PS);
 }