mac80211: allow drivers to request DTIM period

Some features require knowing the DTIM period
before associating. This implements the ability
to wait for a beacon in mac80211 before assoc
to provide this value. It is optional since
most likely not all drivers will need this.

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

1 files changed, 4 insertions, 0 deletions

diff --git a/net/mac80211/scan.c b/net/mac80211/scan.c
index 41635b2c91bf..41f20fb7e670 100644
--- a/net/mac80211/scan.c
+++ b/net/mac80211/scan.c
@@ -114,6 +114,10 @@ ieee80211_bss_info_update(struct ieee80211_local *local,
                 bss->dtim_period = tim_ie->dtim_period;
         }
 
+        /* If the beacon had no TIM IE, or it was invalid, use 1 */
+        if (beacon && !bss->dtim_period)
+                bss->dtim_period = 1;
+
         /* replace old supported rates if we get new values */
         srlen = 0;
         if (elems->supp_rates) {