wireless: report reasonable bitrate for MCS rates through wext

[karo-tx-linux.git] / net / wireless / util.c

diff --git a/net/wireless/util.c b/net/wireless/util.c
index 59361fdcb5d03898b8d16ce5c7fbe637954a8cbf..a3c841a255dbb19db337c44d7ede680362cfce90 100644 (file)
--- a/net/wireless/util.c
+++ b/net/wireless/util.c
@@ -720,3 +720,36 @@ int cfg80211_change_iface(struct cfg80211_registered_device *rdev,
 
        return err;
 }
+
+u16 cfg80211_calculate_bitrate(struct rate_info *rate)
+{
+       int modulation, streams, bitrate;
+
+       if (!(rate->flags & RATE_INFO_FLAGS_MCS))
+               return rate->legacy;
+
+       /* the formula below does only work for MCS values smaller than 32 */
+       if (rate->mcs >= 32)
+               return 0;
+
+       modulation = rate->mcs & 7;
+       streams = (rate->mcs >> 3) + 1;
+
+       bitrate = (rate->flags & RATE_INFO_FLAGS_40_MHZ_WIDTH) ?
+                       13500000 : 6500000;
+
+       if (modulation < 4)
+               bitrate *= (modulation + 1);
+       else if (modulation == 4)
+               bitrate *= (modulation + 2);
+       else
+               bitrate *= (modulation + 3);
+
+       bitrate *= streams;
+
+       if (rate->flags & RATE_INFO_FLAGS_SHORT_GI)
+               bitrate = (bitrate / 9) * 10;
+
+       /* do NOT round down here */
+       return (bitrate + 50000) / 100000;
+}