wireless: report reasonable bitrate for MCS rates through wext

patch from linux-next, can be feeded to stable once hit linux-2.6.
discovered on linux-2.6.32 F12 branch.

svn path=/dists/trunk/linux-2.6/; revision=15176

3 files changed, 149 insertions, 0 deletions

diff --git a/debian/changelog b/debian/changelog
index 9deb0e6cb068..204b7ec1927b 100644
--- a/debian/changelog
+++ b/debian/changelog
@@ -12,6 +12,7 @@ linux-2.6 (2.6.32-9) UNRELEASED; urgency=low
   * Postinst only write kernel-img.conf for palo boxes.
   * Enable VT_HW_CONSOLE_BINDING for unbinding efifb. (closes: #569314)
   * hwmon: Add driver for VIA CPU core temperature.
+  * wireless: report reasonable bitrate for MCS rates through wext.
 
   [ Bastian Blank ]
   * Restrict access to sensitive SysRq keys by default.
diff --git a/debian/patches/features/all/wireless-report-reasonable-bitrate-for-MCS-rates-th.patch b/debian/patches/features/all/wireless-report-reasonable-bitrate-for-MCS-rates-th.patch
new file mode 100644
index 000000000000..91838670357b
--- /dev/null
+++ b/debian/patches/features/all/wireless-report-reasonable-bitrate-for-MCS-rates-th.patch
@@ -0,0 +1,147 @@
+From 254416aae70ab2e6b57fd79782c8a67196234d02 Mon Sep 17 00:00:00 2001
+From: John W. Linville <linville@tuxdriver.com>
+Date: Wed, 9 Dec 2009 16:43:52 -0500
+Subject: [PATCH] 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>
+---
+ net/wireless/core.h        |    2 ++
+ net/wireless/nl80211.c     |   37 ++-----------------------------------
+ net/wireless/util.c        |   33 +++++++++++++++++++++++++++++++++
+ net/wireless/wext-compat.c |    5 +----
+ 4 files changed, 38 insertions(+), 39 deletions(-)
+
+diff --git a/net/wireless/core.h b/net/wireless/core.h
+index 4ef3efc..35b7121 100644
+--- 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;
+ }
+-- 
+1.5.6.5
+
diff --git a/debian/patches/series/9 b/debian/patches/series/9
index 9c5eaa1863cc..74cfcdca332b 100644
--- a/debian/patches/series/9
+++ b/debian/patches/series/9
@@ -6,3 +6,4 @@
 + features/all/macvlan-implement-bridge-VEPA-and-private-mode.patch
 + features/all/macvlan-export-macvlan-mode-through-netlink.patch
 + features/all/hwmon-Add-driver-for-VIA-CPU-core-temperature.patch
++ features/all/wireless-report-reasonable-bitrate-for-MCS-rates-th.patch