mac80211: wait for beacon before enabling powersave

Because DTIM information is required for powersave
but is only conveyed in beacons, wait for a beacon
before enabling powersave, and change the way the
information is conveyed to the driver accordingly.

mwl8k doesn't currently seem to implement PS but
requires the DTIM period in a different way; after
talking to Lennert we agreed to just have mwl8k do
the parsing itself in the finalize_join work.

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

1 files changed, 24 insertions, 3 deletions

diff --git a/net/mac80211/mlme.c b/net/mac80211/mlme.c
index 1e1d16c55ee5..86c6ad1b058d 100644
--- a/net/mac80211/mlme.c
+++ b/net/mac80211/mlme.c
@@ -484,6 +484,7 @@ void ieee80211_recalc_ps(struct ieee80211_local *local, s32 latency)
 
         if (count == 1 && found->u.mgd.powersave &&
             found->u.mgd.associated &&
+            found->u.mgd.associated->beacon_ies &&
             !(found->u.mgd.flags & (IEEE80211_STA_BEACON_POLL |
                                     IEEE80211_STA_CONNECTION_POLL))) {
                 s32 beaconint_us;
@@ -497,14 +498,22 @@ void ieee80211_recalc_ps(struct ieee80211_local *local, s32 latency)
                 if (beaconint_us > latency) {
                         local->ps_sdata = NULL;
                 } else {
-                        u8 dtimper = found->vif.bss_conf.dtim_period;
+                        struct ieee80211_bss *bss;
                         int maxslp = 1;
+                        u8 dtimper;
 
-                        if (dtimper > 1)
+                        bss = (void *)found->u.mgd.associated->priv;
+                        dtimper = bss->dtim_period;
+
+                        /* If the TIM IE is invalid, pretend the value is 1 */
+                        if (!dtimper)
+                                dtimper = 1;
+                        else if (dtimper > 1)
                                 maxslp = min_t(int, dtimper,
                                                     latency / beaconint_us);
 
                         local->hw.conf.max_sleep_period = maxslp;
+                        local->hw.conf.ps_dtim_period = dtimper;
                         local->ps_sdata = found;
                 }
         } else {
@@ -702,7 +711,6 @@ static void ieee80211_set_associated(struct ieee80211_sub_if_data *sdata,
         /* set timing information */
         sdata->vif.bss_conf.beacon_int = cbss->beacon_interval;
         sdata->vif.bss_conf.timestamp = cbss->tsf;
-        sdata->vif.bss_conf.dtim_period = bss->dtim_period;
 
         bss_info_changed |= BSS_CHANGED_BEACON_INT;
         bss_info_changed |= ieee80211_handle_bss_capability(sdata,
@@ -1168,6 +1176,13 @@ static void ieee80211_rx_bss_info(struct ieee80211_sub_if_data *sdata,
         int freq;
         struct ieee80211_bss *bss;
         struct ieee80211_channel *channel;
+        bool need_ps = false;
+
+        if (sdata->u.mgd.associated) {
+                bss = (void *)sdata->u.mgd.associated->priv;
+                /* not previously set so we may need to recalc */
+                need_ps = !bss->dtim_period;
+        }
 
         if (elems->ds_params && elems->ds_params_len == 1)
                 freq = ieee80211_channel_to_frequency(elems->ds_params[0]);
@@ -1187,6 +1202,12 @@ static void ieee80211_rx_bss_info(struct ieee80211_sub_if_data *sdata,
         if (!sdata->u.mgd.associated)
                 return;
 
+        if (need_ps) {
+                mutex_lock(&local->iflist_mtx);
+                ieee80211_recalc_ps(local, -1);
+                mutex_unlock(&local->iflist_mtx);
+        }
+
         if (elems->ch_switch_elem && (elems->ch_switch_elem_len == 3) &&
             (memcmp(mgmt->bssid, sdata->u.mgd.associated->bssid,
                                                         ETH_ALEN) == 0)) {