wireless: report reasonable bitrate for MCS rates through wext
Previously, cfg80211 had reported "0" for MCS (i.e. 802.11n) bitrates
through the wireless extensions interface. However, nl80211 was
converting MCS rates into a reasonable bitrate number. This patch moves
the nl80211 code to cfg80211 where it is now shared between both the
nl80211 interface and the wireless extensions interface.
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/net/wireless/util.c b/net/wireless/util.c
index 59361fd..a3c841a 100644
--- a/net/wireless/util.c
+++ b/net/wireless/util.c
@@ -720,3 +720,36 @@
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;
+}