mac80211: explicitly notify drivers of frame release

iwlwifi needs to know the number of frames that are
going to be sent to a station while it is asleep so
it can properly handle the uCode blocking of that
station.

Before uAPSD, we got by by telling the device that
a single frame was going to be released whenever we
encountered IEEE80211_TX_CTL_POLL_RESPONSE. With
uAPSD, however, that is no longer possible since
there could be more than a single frame.

To support this model, add a new callback to notify
drivers when frames are going to be released.

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

1 files changed, 25 insertions, 9 deletions

diff --git a/net/mac80211/sta_info.c b/net/mac80211/sta_info.c
index a00358224cd5..907b42081f3c 100644
--- a/net/mac80211/sta_info.c
+++ b/net/mac80211/sta_info.c
@@ -1169,7 +1169,7 @@ void ieee80211_sta_ps_deliver_wakeup(struct sta_info *sta)
 
 static void ieee80211_send_null_response(struct ieee80211_sub_if_data *sdata,
                                          struct sta_info *sta, int tid,
-                                         bool uapsd)
+                                         enum ieee80211_frame_release_type reason)
 {
         struct ieee80211_local *local = sdata->local;
         struct ieee80211_qos_hdr *nullfunc;
@@ -1210,7 +1210,7 @@ static void ieee80211_send_null_response(struct ieee80211_sub_if_data *sdata,
 
                 nullfunc->qos_ctrl = cpu_to_le16(tid);
 
-                if (uapsd)
+                if (reason == IEEE80211_FRAME_RELEASE_UAPSD)
                         nullfunc->qos_ctrl |=
                                 cpu_to_le16(IEEE80211_QOS_CTL_EOSP);
         }
@@ -1227,6 +1227,8 @@ static void ieee80211_send_null_response(struct ieee80211_sub_if_data *sdata,
                        IEEE80211_TX_STATUS_EOSP |
                        IEEE80211_TX_CTL_REQ_TX_STATUS;
 
+        drv_allow_buffered_frames(local, sta, BIT(tid), 1, reason, false);
+
         ieee80211_xmit(sdata, skb);
 }
 
@@ -1324,20 +1326,24 @@ ieee80211_sta_ps_deliver_response(struct sta_info *sta,
                 /* This will evaluate to 1, 3, 5 or 7. */
                 tid = 7 - ((ffs(~ignored_acs) - 1) << 1);
 
-                ieee80211_send_null_response(sdata, sta, tid,
-                                reason == IEEE80211_FRAME_RELEASE_UAPSD);
+                ieee80211_send_null_response(sdata, sta, tid, reason);
                 return;
         }
 
         if (!driver_release_tids) {
                 struct sk_buff_head pending;
                 struct sk_buff *skb;
+                int num = 0;
+                u16 tids = 0;
 
                 skb_queue_head_init(&pending);
 
                 while ((skb = __skb_dequeue(&frames))) {
                         struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
                         struct ieee80211_hdr *hdr = (void *) skb->data;
+                        u8 *qoshdr = NULL;
+
+                        num++;
 
                         /*
                          * Tell TX path to send this frame even though the
@@ -1357,19 +1363,29 @@ ieee80211_sta_ps_deliver_response(struct sta_info *sta,
                                 hdr->frame_control |=
                                         cpu_to_le16(IEEE80211_FCTL_MOREDATA);
 
+                        if (ieee80211_is_data_qos(hdr->frame_control) ||
+                            ieee80211_is_qos_nullfunc(hdr->frame_control))
+                                qoshdr = ieee80211_get_qos_ctl(hdr);
+
+                        /* set EOSP for the frame */
                         if (reason == IEEE80211_FRAME_RELEASE_UAPSD &&
-                            skb_queue_empty(&frames)) {
-                                /* set EOSP for the frame */
-                                u8 *p = ieee80211_get_qos_ctl(hdr);
-                                *p |= IEEE80211_QOS_CTL_EOSP;
-                        }
+                            qoshdr && skb_queue_empty(&frames))
+                                *qoshdr |= IEEE80211_QOS_CTL_EOSP;
 
                         info->flags |= IEEE80211_TX_STATUS_EOSP |
                                        IEEE80211_TX_CTL_REQ_TX_STATUS;
 
+                        if (qoshdr)
+                                tids |= BIT(*qoshdr & IEEE80211_QOS_CTL_TID_MASK);
+                        else
+                                tids |= BIT(0);
+
                         __skb_queue_tail(&pending, skb);
                 }
 
+                drv_allow_buffered_frames(local, sta, tids, num,
+                                          reason, more_data);
+
                 ieee80211_add_pending_skbs(local, &pending);
 
                 sta_info_recalc_tim(sta);