[patch 120/164] wireless: report reasonable bitrate for MCS rates through wext

Greg KH
2010-07-01T21:06:11Z

2.6.33-stable review patch. If anyone has any objections, please let me know.

------------------

From: John W. Linville <linville@tuxdriver.com>

commit 254416aae70ab2e6b57fd79782c8a67196234d02 upstream.

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>
Cc: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

--- a/net/wireless/core.h
+++ b/net/wireless/core.h
@@ -378,6 +378,8 @@ int rdev_set_freq(struct cfg80211_registered_device *rdev,
struct wireless_dev *for_wdev,
int freq, enum nl80211_channel_type channel_type);

+u16 cfg80211_calculate_bitrate(struct rate_info *rate);
+
#ifdef CONFIG_CFG80211_DEVELOPER_WARNINGS
#define CFG80211_DEV_WARN_ON(cond) WARN_ON(cond)
#else
diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c
index a602843..7cb0d64 100644
--- a/net/wireless/nl80211.c
+++ b/net/wireless/nl80211.c
@@ -1637,39 +1637,6 @@ static int parse_station_flags(struct genl_info *info,
return 0;
}

-static u16 nl80211_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;
-}
-
static int nl80211_send_station(struct sk_buff *msg, u32 pid, u32 seq,
int flags, struct net_device *dev,
u8 *mac_addr, struct station_info *sinfo)
@@ -1716,8 +1683,8 @@ static int nl80211_send_station(struct sk_buff *msg, u32 pid, u32 seq,
if (!txrate)
goto nla_put_failure;

- /* nl80211_calculate_bitrate will return 0 for mcs >= 32 */
- bitrate = nl80211_calculate_bitrate(&sinfo->txrate);
+ /* cfg80211_calculate_bitrate will return 0 for mcs >= 32 */
+ bitrate = cfg80211_calculate_bitrate(&sinfo->txrate);
if (bitrate > 0)
NLA_PUT_U16(msg, NL80211_RATE_INFO_BITRATE, bitrate);

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 @@ 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;
+}
diff --git a/net/wireless/wext-compat.c b/net/wireless/wext-compat.c
index 584eb48..2fa8de1 100644
--- a/net/wireless/wext-compat.c
+++ b/net/wireless/wext-compat.c
@@ -1256,10 +1256,7 @@ int cfg80211_wext_giwrate(struct net_device *dev,
if (!(sinfo.filled & STATION_INFO_TX_BITRATE))
return -EOPNOTSUPP;

- rate->value = 0;
-
- if (!(sinfo.txrate.flags & RATE_INFO_FLAGS_MCS))
- rate->value = 100000 * sinfo.txrate.legacy;
+ rate->value = 100000 * cfg80211_calculate_bitrate(&sinfo.txrate);

return 0;
}