mac80211: select and adjust bitrates according to channel mode

The various components accessing the bitrates table must use consider
the used channel bandwidth to select only available rates or calculate
the bitrate correctly.

There are some rates in reduced bandwidth modes which can't be
represented as multiples of 500kbps, like 2.25 MBit/s in 5 MHz mode. The
standard suggests to round up to the next multiple of 500kbps, just do
that in mac80211 as well.

Signed-off-by: Simon Wunderlich <siwu@hrz.tu-chemnitz.de>
Signed-off-by: Mathias Kretschmer <mathias.kretschmer@fokus.fraunhofer.de>
[make rate unsigned in ieee80211_add_tx_radiotap_header(), squash fix]
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>

1 files changed, 13 insertions, 5 deletions

diff --git a/net/mac80211/status.c b/net/mac80211/status.c
index 43439203f4e4..6ad4c14385ef 100644
--- a/net/mac80211/status.c
+++ b/net/mac80211/status.c
@@ -252,9 +252,10 @@ static int ieee80211_tx_radiotap_len(struct ieee80211_tx_info *info)
         return len;
 }
 
-static void ieee80211_add_tx_radiotap_header(struct ieee80211_supported_band
-                                             *sband, struct sk_buff *skb,
-                                             int retry_count, int rtap_len)
+static void
+ieee80211_add_tx_radiotap_header(struct ieee80211_supported_band *sband,
+                                 struct sk_buff *skb, int retry_count,
+                                 int rtap_len, int shift)
 {
         struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
@@ -280,8 +281,11 @@ static void ieee80211_add_tx_radiotap_header(struct ieee80211_supported_band
         /* IEEE80211_RADIOTAP_RATE */
         if (info->status.rates[0].idx >= 0 &&
             !(info->status.rates[0].flags & IEEE80211_TX_RC_MCS)) {
+                u16 rate;
+
                 rthdr->it_present |= cpu_to_le32(1 << IEEE80211_RADIOTAP_RATE);
-                *pos = sband->bitrates[info->status.rates[0].idx].bitrate / 5;
+                rate = sband->bitrates[info->status.rates[0].idx].bitrate;
+                *pos = DIV_ROUND_UP(rate, 5 * (1 << shift));
                 /* padding for tx flags */
                 pos += 2;
         }
@@ -424,6 +428,7 @@ void ieee80211_tx_status(struct ieee80211_hw *hw, struct sk_buff *skb)
         bool acked;
         struct ieee80211_bar *bar;
         int rtap_len;
+        int shift = 0;
 
         for (i = 0; i < IEEE80211_TX_MAX_RATES; i++) {
                 if ((info->flags & IEEE80211_TX_CTL_AMPDU) &&
@@ -458,6 +463,8 @@ void ieee80211_tx_status(struct ieee80211_hw *hw, struct sk_buff *skb)
                 if (!ether_addr_equal(hdr->addr2, sta->sdata->vif.addr))
                         continue;
 
+                shift = ieee80211_vif_get_shift(&sta->sdata->vif);
+
                 if (info->flags & IEEE80211_TX_STATUS_EOSP)
                         clear_sta_flag(sta, WLAN_STA_SP);
 
@@ -624,7 +631,8 @@ void ieee80211_tx_status(struct ieee80211_hw *hw, struct sk_buff *skb)
                 dev_kfree_skb(skb);
                 return;
         }
-        ieee80211_add_tx_radiotap_header(sband, skb, retry_count, rtap_len);
+        ieee80211_add_tx_radiotap_header(sband, skb, retry_count, rtap_len,
+                                         shift);
 
         /* XXX: is this sufficient for BPF? */
         skb_set_mac_header(skb, 0);