mac80211: handle MMPDUs at EOSP correctly

If a uAPSD service period ends with an MMPDU, we currently just
send that MMPDU, but it obviously won't get the EOSP bit set as
it doesn't have a QoS header. This contradicts the standard, so
add a QoS-nulldata frame after the MMPDU to properly terminate
the service period with a frame that has EOSP set.

Also fix a bug wrt. the TID for the MMPDU, it shouldn't be set
to 0 unconditionally but use the actual TID that was assigned.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>

1 files changed, 5 insertions, 0 deletions

diff --git a/include/net/mac80211.h b/include/net/mac80211.h
index 25b18877747f..f4ab2fb4d50c 100644
--- a/include/net/mac80211.h
+++ b/include/net/mac80211.h
@@ -2119,6 +2119,11 @@ void ieee80211_free_txskb(struct ieee80211_hw *hw, struct sk_buff *skb);
  * appropriately (only the last frame may have %IEEE80211_TX_STATUS_EOSP)
  * and also take care of the EOSP and MORE_DATA bits in the frame.
  * The driver may also use ieee80211_sta_eosp() in this case.
+ *
+ * Note that if the driver ever buffers frames other than QoS-data
+ * frames, it must take care to never send a non-QoS-data frame as
+ * the last frame in a service period, adding a QoS-nulldata frame
+ * after a non-QoS-data frame if needed.
  */
 
 /**