mac80211/drivers: rewrite the rate control API

So after the previous changes we were still unhappy with how
convoluted the API is and decided to make things simpler for
everybody. This completely changes the rate control API, now
taking into account 802.11n with MCS rates and more control,
most drivers don't support that though.

Signed-off-by: Felix Fietkau <nbd@openwrt.org>
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 41 insertions, 13 deletions

diff --git a/net/mac80211/main.c b/net/mac80211/main.c
index ffff54944f9d..88c1975a97a5 100644
--- a/net/mac80211/main.c
+++ b/net/mac80211/main.c
@@ -41,6 +41,8 @@
  */
 struct ieee80211_tx_status_rtap_hdr {
         struct ieee80211_radiotap_header hdr;
+        u8 rate;
+        u8 padding_for_rate;
         __le16 tx_flags;
         u8 data_retries;
 } __attribute__ ((packed));
@@ -465,13 +467,28 @@ void ieee80211_tx_status(struct ieee80211_hw *hw, struct sk_buff *skb)
         struct ieee80211_sub_if_data *sdata;
         struct net_device *prev_dev = NULL;
         struct sta_info *sta;
+        int retry_count = -1, i;
+
+        for (i = 0; i < IEEE80211_TX_MAX_RATES; i++) {
+                /* the HW cannot have attempted that rate */
+                if (i >= hw->max_rates) {
+                        info->status.rates[i].idx = -1;
+                        info->status.rates[i].count = 0;
+                }
+
+                retry_count += info->status.rates[i].count;
+        }
+        if (retry_count < 0)
+                retry_count = 0;
 
         rcu_read_lock();
 
+        sband = local->hw.wiphy->bands[info->band];
+
         sta = sta_info_get(local, hdr->addr1);
 
         if (sta) {
-                if (info->status.excessive_retries &&
+                if (!(info->flags & IEEE80211_TX_STAT_ACK) &&
                     test_sta_flags(sta, WLAN_STA_PS)) {
                         /*
                          * The STA is in power save mode, so assume
@@ -502,12 +519,11 @@ void ieee80211_tx_status(struct ieee80211_hw *hw, struct sk_buff *skb)
                         rcu_read_unlock();
                         return;
                 } else {
-                        if (info->status.excessive_retries)
+                        if (!(info->flags & IEEE80211_TX_STAT_ACK))
                                 sta->tx_retry_failed++;
-                        sta->tx_retry_count += info->status.retry_count;
+                        sta->tx_retry_count += retry_count;
                 }
 
-                sband = local->hw.wiphy->bands[info->band];
                 rate_control_tx_status(local, sband, sta, skb);
         }
 
@@ -528,9 +544,9 @@ void ieee80211_tx_status(struct ieee80211_hw *hw, struct sk_buff *skb)
                         local->dot11TransmittedFrameCount++;
                         if (is_multicast_ether_addr(hdr->addr1))
                                 local->dot11MulticastTransmittedFrameCount++;
-                        if (info->status.retry_count > 0)
+                        if (retry_count > 0)
                                 local->dot11RetryCount++;
-                        if (info->status.retry_count > 1)
+                        if (retry_count > 1)
                                 local->dot11MultipleRetryCount++;
                 }
 
@@ -574,19 +590,30 @@ void ieee80211_tx_status(struct ieee80211_hw *hw, struct sk_buff *skb)
         rthdr->hdr.it_len = cpu_to_le16(sizeof(*rthdr));
         rthdr->hdr.it_present =
                 cpu_to_le32((1 << IEEE80211_RADIOTAP_TX_FLAGS) |
-                            (1 << IEEE80211_RADIOTAP_DATA_RETRIES));
+                            (1 << IEEE80211_RADIOTAP_DATA_RETRIES) |
+                            (1 << IEEE80211_RADIOTAP_RATE));
 
         if (!(info->flags & IEEE80211_TX_STAT_ACK) &&
             !is_multicast_ether_addr(hdr->addr1))
                 rthdr->tx_flags |= cpu_to_le16(IEEE80211_RADIOTAP_F_TX_FAIL);
 
-        if ((info->flags & IEEE80211_TX_CTL_USE_RTS_CTS) &&
-            (info->flags & IEEE80211_TX_CTL_USE_CTS_PROTECT))
+        /*
+         * XXX: Once radiotap gets the bitmap reset thing the vendor
+         *      extensions proposal contains, we can actually report
+         *      the whole set of tries we did.
+         */
+        if ((info->status.rates[0].flags & IEEE80211_TX_RC_USE_RTS_CTS) ||
+            (info->status.rates[0].flags & IEEE80211_TX_RC_USE_CTS_PROTECT))
                 rthdr->tx_flags |= cpu_to_le16(IEEE80211_RADIOTAP_F_TX_CTS);
-        else if (info->flags & IEEE80211_TX_CTL_USE_RTS_CTS)
+        else if (info->status.rates[0].flags & IEEE80211_TX_RC_USE_RTS_CTS)
                 rthdr->tx_flags |= cpu_to_le16(IEEE80211_RADIOTAP_F_TX_RTS);
+        if (info->status.rates[0].idx >= 0 &&
+            !(info->status.rates[0].flags & IEEE80211_TX_RC_MCS))
+                rthdr->rate = sband->bitrates[
+                                info->status.rates[0].idx].bitrate / 5;
 
-        rthdr->data_retries = info->status.retry_count;
+        /* for now report the total retry_count */
+        rthdr->data_retries = retry_count;
 
         /* XXX: is this sufficient for BPF? */
         skb_set_mac_header(skb, 0);
@@ -671,8 +698,9 @@ struct ieee80211_hw *ieee80211_alloc_hw(size_t priv_data_len,
         BUG_ON(!ops->configure_filter);
         local->ops = ops;
 
-        local->hw.queues = 1; /* default */
-
+        /* set up some defaults */
+        local->hw.queues = 1;
+        local->hw.max_rates = 1;
         local->rts_threshold = IEEE80211_MAX_RTS_THRESHOLD;
         local->fragmentation_threshold = IEEE80211_MAX_FRAG_THRESHOLD;
         local->hw.conf.long_frame_max_tx_count = 4;