mac80211: add helper for management / no-ack frame rate decision

All current rate control algorithms agree to send management and no-ack
frames at the lowest rate. They also agree to do this when sta
and the private rate control data is NULL. We add a hlper to mac80211
for this and simplify the rate control algorithm code.

Developers wishing to make enhancements to rate control algorithms
are for broadcast/multicast can opt to not use this in their
gate_rate() mac80211 callback.

Cc: Zhu Yi <yi.zhu@intel.com>
Acked-by: Reinette Chatre <reinette.chatre@intel.com>
Cc: ipw3945-devel@lists.sourceforge.net
Cc: Gabor Juhos <juhosg@openwrt.org>
Acked-by: Felix Fietkau <nbd@openwrt.org>
Cc: Derek Smithies <derek@indranet.co.nz>
Cc: Chittajit Mitra <Chittajit.Mitra@Atheros.com>
Signed-off-by: Luis R. Rodriguez <lrodriguez@atheros.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

3 files changed, 5 insertions, 29 deletions

diff --git a/drivers/net/wireless/ath/ath9k/rc.c b/drivers/net/wireless/ath/ath9k/rc.c
index 2c72901adbee..630fcf46e0dd 100644
--- a/drivers/net/wireless/ath/ath9k/rc.c
+++ b/drivers/net/wireless/ath/ath9k/rc.c
@@ -1518,23 +1518,11 @@ exit:
 static void ath_get_rate(void *priv, struct ieee80211_sta *sta, void *priv_sta,
                          struct ieee80211_tx_rate_control *txrc)
 {
-        struct ieee80211_supported_band *sband = txrc->sband;
-        struct sk_buff *skb = txrc->skb;
-        struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
-        struct ieee80211_tx_info *tx_info = IEEE80211_SKB_CB(skb);
         struct ath_softc *sc = priv;
         struct ath_rate_priv *ath_rc_priv = priv_sta;
-        __le16 fc = hdr->frame_control;
 
-        /* lowest rate for management and NO_ACK frames */
-        if (!ieee80211_is_data(fc) ||
-            tx_info->flags & IEEE80211_TX_CTL_NO_ACK || !sta) {
-                tx_info->control.rates[0].idx = rate_lowest_index(sband, sta);
-                tx_info->control.rates[0].count =
-                        (tx_info->flags & IEEE80211_TX_CTL_NO_ACK) ?
-                                1 : ATH_MGT_TXMAXTRY;
+        if (rate_control_send_low(sta, priv_sta, txrc))
                 return;
-        }
 
         /* Find tx rate for unicast frames */
         ath_rc_ratefind(sc, ath_rc_priv, txrc);
diff --git a/drivers/net/wireless/iwlwifi/iwl-3945-rs.c b/drivers/net/wireless/iwlwifi/iwl-3945-rs.c
index 2b776924d5e7..a16bd4147eac 100644
--- a/drivers/net/wireless/iwlwifi/iwl-3945-rs.c
+++ b/drivers/net/wireless/iwlwifi/iwl-3945-rs.c
@@ -673,7 +673,6 @@ static void rs_get_rate(void *priv_r, struct ieee80211_sta *sta,
         s8 scale_action = 0;
         unsigned long flags;
         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
-        __le16 fc;
         u16 rate_mask = sta ? sta->supp_rates[sband->band] : 0;
         s8 max_rate_idx = -1;
         struct iwl_priv *priv = (struct iwl_priv *)priv_r;
@@ -681,16 +680,10 @@ static void rs_get_rate(void *priv_r, struct ieee80211_sta *sta,
 
         IWL_DEBUG_RATE(priv, "enter\n");
 
-        /* Send management frames and NO_ACK data using lowest rate. */
-        fc = hdr->frame_control;
-        if (!ieee80211_is_data(fc) || info->flags & IEEE80211_TX_CTL_NO_ACK ||
-            !sta || !priv_sta) {
-                IWL_DEBUG_RATE(priv, "leave: No STA priv data to update!\n");
-                info->control.rates[0].idx = rate_lowest_index(sband, sta);
-                if (info->flags & IEEE80211_TX_CTL_NO_ACK)
-                        info->control.rates[0].count = 1;
+        if (rate_control_send_low(sta, priv_sta, txrc))
                 return;
-        }
+
+        rate_mask = sta->supp_rates[sband->band];
 
         /* get user max rate if set */
         max_rate_idx = txrc->max_rate_idx;
diff --git a/drivers/net/wireless/iwlwifi/iwl-agn-rs.c b/drivers/net/wireless/iwlwifi/iwl-agn-rs.c
index 3fea027f35d1..63280411fd58 100644
--- a/drivers/net/wireless/iwlwifi/iwl-agn-rs.c
+++ b/drivers/net/wireless/iwlwifi/iwl-agn-rs.c
@@ -2481,13 +2481,8 @@ static void rs_get_rate(void *priv_r, struct ieee80211_sta *sta, void *priv_sta,
         }
 
         /* Send management frames and NO_ACK data using lowest rate. */
-        if (!ieee80211_is_data(hdr->frame_control) ||
-            info->flags & IEEE80211_TX_CTL_NO_ACK || !sta || !lq_sta) {
-                info->control.rates[0].idx = rate_lowest_index(sband, sta);
-                if (info->flags & IEEE80211_TX_CTL_NO_ACK)
-                        info->control.rates[0].count = 1;
+        if (rate_control_send_low(sta, priv_sta, txrc))
                 return;
-        }
 
         rate_idx  = lq_sta->last_txrate_idx;