mac80211: remove channel use statistics

The useless channel use statistics are quite a lot of code, currently
use integer divisions in the packet fast path, are rather inaccurate
since they do not account for retries and finally nobody even cares.
Hence, remove them completely.

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

1 files changed, 9 insertions, 64 deletions

diff --git a/net/mac80211/tx.c b/net/mac80211/tx.c
index 9273651d3d7c..baa1be0671e5 100644
--- a/net/mac80211/tx.c
+++ b/net/mac80211/tx.c
@@ -761,73 +761,18 @@ ieee80211_tx_h_encrypt(struct ieee80211_tx_data *tx)
 static ieee80211_tx_result
 ieee80211_tx_h_stats(struct ieee80211_tx_data *tx)
 {
-        struct ieee80211_local *local = tx->local;
-        struct sk_buff *skb = tx->skb;
-        struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
-        u32 load = 0, hdrtime;
-        struct ieee80211_rate *rate;
-        struct ieee80211_supported_band *sband;
-        struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
-
-        sband = tx->local->hw.wiphy->bands[tx->channel->band];
-        rate = &sband->bitrates[tx->rate_idx];
-
-        /* TODO: this could be part of tx_status handling, so that the number
-         * of retries would be known; TX rate should in that case be stored
-         * somewhere with the packet */
-
-        /* Estimate total channel use caused by this frame */
-
-        /* 1 bit at 1 Mbit/s takes 1 usec; in channel_use values,
-         * 1 usec = 1/8 * (1080 / 10) = 13.5 */
-
-        if (tx->channel->band == IEEE80211_BAND_5GHZ ||
-            (tx->channel->band == IEEE80211_BAND_2GHZ &&
-             rate->flags & IEEE80211_RATE_ERP_G))
-                hdrtime = CHAN_UTIL_HDR_SHORT;
-        else
-                hdrtime = CHAN_UTIL_HDR_LONG;
-
-        load = hdrtime;
-        if (!is_multicast_ether_addr(hdr->addr1))
-                load += hdrtime;
-
-        if (info->flags & IEEE80211_TX_CTL_USE_RTS_CTS)
-                load += 2 * hdrtime;
-        else if (info->flags & IEEE80211_TX_CTL_USE_CTS_PROTECT)
-                load += hdrtime;
+        int i;
 
-        /* TODO: optimise again */
-        load += skb->len * CHAN_UTIL_RATE_LCM / rate->bitrate;
+        if (!tx->sta)
+                return TX_CONTINUE;
 
+        tx->sta->tx_packets++;
+        tx->sta->tx_fragments++;
+        tx->sta->tx_bytes += tx->skb->len;
         if (tx->extra_frag) {
-                int i;
-                for (i = 0; i < tx->num_extra_frag; i++) {
-                        load += 2 * hdrtime;
-                        load += tx->extra_frag[i]->len *
-                                rate->bitrate;
-                }
-        }
-
-        /* Divide channel_use by 8 to avoid wrapping around the counter */
-        load >>= CHAN_UTIL_SHIFT;
-        local->channel_use_raw += load;
-        if (tx->sta)
-                tx->sta->channel_use_raw += load;
-        tx->sdata->channel_use_raw += load;
-
-        if (tx->sta) {
-                tx->sta->tx_packets++;
-                tx->sta->tx_fragments++;
-                tx->sta->tx_bytes += tx->skb->len;
-                if (tx->extra_frag) {
-                        int i;
-                        tx->sta->tx_fragments += tx->num_extra_frag;
-                        for (i = 0; i < tx->num_extra_frag; i++) {
-                                tx->sta->tx_bytes +=
-                                        tx->extra_frag[i]->len;
-                        }
-                }
+                tx->sta->tx_fragments += tx->num_extra_frag;
+                for (i = 0; i < tx->num_extra_frag; i++)
+                        tx->sta->tx_bytes += tx->extra_frag[i]->len;
         }
 
         return TX_CONTINUE;