mac80211: add flag to indicate HW only Tx-agg setup support

When this flag is set, Tx A-MPDU sessions will not be started by
mac80211. This flag is required for devices that support Tx A-MPDU setup
in hardware.
Signed-off-by: Arik Nemtsov <arik@wizery.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

include/net/mac80211.h

@@ -1096,6 +1096,10 @@ enum sta_notify_cmd {
  *	stations based on the PM bit of incoming frames.
  *	Use ieee80211_start_ps()/ieee8021_end_ps() to manually configure
  *	the PS mode of connected stations.
+ *
+ * @IEEE80211_HW_TX_AMPDU_SETUP_IN_HW: The device handles TX A-MPDU session
+ *	setup strictly in HW. mac80211 should not attempt to do this in
+ *	software.
  */
 enum ieee80211_hw_flags {
 	IEEE80211_HW_HAS_RATE_CONTROL			= 1<<0,
@@ -1121,6 +1125,7 @@ enum ieee80211_hw_flags {
 	IEEE80211_HW_SUPPORTS_CQM_RSSI			= 1<<20,
 	IEEE80211_HW_SUPPORTS_PER_STA_GTK		= 1<<21,
 	IEEE80211_HW_AP_LINK_PS				= 1<<22,
+	IEEE80211_HW_TX_AMPDU_SETUP_IN_HW		= 1<<23,
 };
 
 /**

net/mac80211/agg-tx.c

@@ -360,7 +360,8 @@ int ieee80211_start_tx_ba_session(struct ieee80211_sta *pubsta, u16 tid,
 		return -EINVAL;
 
 	if ((tid >= STA_TID_NUM) ||
-	    !(local->hw.flags & IEEE80211_HW_AMPDU_AGGREGATION))
+	    !(local->hw.flags & IEEE80211_HW_AMPDU_AGGREGATION) ||
+	    (local->hw.flags & IEEE80211_HW_TX_AMPDU_SETUP_IN_HW))
 		return -EINVAL;
 
 #ifdef CONFIG_MAC80211_HT_DEBUG

net/mac80211/debugfs.c

@@ -350,6 +350,8 @@ static ssize_t hwflags_read(struct file *file, char __user *user_buf,
 		sf += snprintf(buf + sf, mxln - sf, "SUPPORTS_PER_STA_GTK\n");
 	if (local->hw.flags & IEEE80211_HW_AP_LINK_PS)
 		sf += snprintf(buf + sf, mxln - sf, "AP_LINK_PS\n");
+	if (local->hw.flags & IEEE80211_HW_TX_AMPDU_SETUP_IN_HW)
+		sf += snprintf(buf + sf, mxln - sf, "TX_AMPDU_SETUP_IN_HW\n");
 
 	rv = simple_read_from_buffer(user_buf, count, ppos, buf, strlen(buf));
 	kfree(buf);

net/mac80211/tx.c

@@ -1232,7 +1232,8 @@ ieee80211_tx_prepare(struct ieee80211_sub_if_data *sdata,
 		tx->sta = sta_info_get(sdata, hdr->addr1);
 
 	if (tx->sta && ieee80211_is_data_qos(hdr->frame_control) &&
-	    (local->hw.flags & IEEE80211_HW_AMPDU_AGGREGATION)) {
+	    (local->hw.flags & IEEE80211_HW_AMPDU_AGGREGATION) &&
+	    !(local->hw.flags & IEEE80211_HW_TX_AMPDU_SETUP_IN_HW)) {
 		struct tid_ampdu_tx *tid_tx;
 
 		qc = ieee80211_get_qos_ctl(hdr);