On Wednesday 10 December 2008 10:05:50 Johannes Berg wrote:
> Uh huh, it's a huge table, and very irregular. Not very inclined to copy
> that right now. What's wrong with deferring it until somebody actually
> implements these rates?
Okay... I will try to implement a complete version of the function when I get
access to the table... here is a modified patch with two warnings about the
missing datarates. It will return 0 for mcs >= 32.
Just a question, did someone with 802.11n hardware test this patches ? I hope
I will have some hardware myself at the end of the year, but at the moment
it's untested.
Henning
--------------------------
diff --git a/include/linux/nl80211.h b/include/linux/nl80211.h
index 56450b4..cc93e7a 100644
--- a/include/linux/nl80211.h
+++ b/include/linux/nl80211.h
@@ -431,14 +431,14 @@ enum nl80211_sta_flags {
* when getting information about the bitrate of a station.
*
* @__NL80211_RATE_INFO_INVALID: attribute number 0 is reserved
- * @NL80211_RATE_INFO_LEGACY: bitrate for 802.11abg (u16, 100kbit/s)
+ * @NL80211_RATE_INFO_BITRATE: total bitrate (u16, 100kbit/s)
* @NL80211_RATE_INFO_MCS: mcs index for 802.11n (u8)
* @NL80211_RATE_INFO_40_MHZ_WIDTH: 40 Mhz dualchannel bitrate
* @NL80211_RATE_INFO_SHORT_GI: 400ns guard interval
*/
enum nl80211_rate_info {
__NL80211_RATE_INFO_INVALID,
- NL80211_RATE_INFO_LEGACY,
+ NL80211_RATE_INFO_BITRATE,
NL80211_RATE_INFO_MCS,
NL80211_RATE_INFO_40_MHZ_WIDTH,
NL80211_RATE_INFO_SHORT_GI,
diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c
index 3f13928..643dcc1 100644
--- a/net/wireless/nl80211.c
+++ b/net/wireless/nl80211.c
@@ -1079,6 +1079,39 @@ static int parse_station_flags(struct nlattr *nla, u32
*staflags)
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)
@@ -1122,13 +1155,13 @@ static int nl80211_send_station(struct sk_buff *msg,
u32 pid, u32 seq,
if (!txrate)
goto nla_put_failure;
-
- if (!(sinfo->txrate.flags & RATE_INFO_FLAGS_MCS))
- NLA_PUT_U16(msg, NL80211_RATE_INFO_LEGACY,
- sinfo->txrate.legacy);
- else
+ /* nl80211_calculate_bitrate will return 0 for mcs >= 32 */
+ NLA_PUT_U16(msg, NL80211_RATE_INFO_BITRATE,
+ nl80211_calculate_bitrate(&sinfo->txrate));
+ if (sinfo->txrate.flags & RATE_INFO_FLAGS_MCS)
NLA_PUT_U8(msg, NL80211_RATE_INFO_MCS,
sinfo->txrate.mcs);
+
if (sinfo->txrate.flags & RATE_INFO_FLAGS_40_MHZ_WIDTH)
NLA_PUT_FLAG(msg, NL80211_RATE_INFO_40_MHZ_WIDTH);
if (sinfo->txrate.flags & RATE_INFO_FLAGS_SHORT_GI)
diff --git a/include/linux/nl80211.h b/include/linux/nl80211.h
index 56450b4..cc93e7a 100644
--- a/include/linux/nl80211.h
+++ b/include/linux/nl80211.h
@@ -431,14 +431,14 @@ enum nl80211_sta_flags {
* when getting information about the bitrate of a station.
*
* @__NL80211_RATE_INFO_INVALID: attribute number 0 is reserved
- * @NL80211_RATE_INFO_LEGACY: bitrate for 802.11abg (u16, 100kbit/s)
+ * @NL80211_RATE_INFO_BITRATE: total bitrate (u16, 100kbit/s)
* @NL80211_RATE_INFO_MCS: mcs index for 802.11n (u8)
* @NL80211_RATE_INFO_40_MHZ_WIDTH: 40 Mhz dualchannel bitrate
* @NL80211_RATE_INFO_SHORT_GI: 400ns guard interval
*/
enum nl80211_rate_info {
__NL80211_RATE_INFO_INVALID,
- NL80211_RATE_INFO_LEGACY,
+ NL80211_RATE_INFO_BITRATE,
NL80211_RATE_INFO_MCS,
NL80211_RATE_INFO_40_MHZ_WIDTH,
NL80211_RATE_INFO_SHORT_GI,
diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c
index 3f13928..643dcc1 100644
--- a/net/wireless/nl80211.c
+++ b/net/wireless/nl80211.c
@@ -1079,6 +1079,39 @@ static int parse_station_flags(struct nlattr *nla, u32 *staflags)
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)
@@ -1122,13 +1155,13 @@ static int nl80211_send_station(struct sk_buff *msg, u32 pid, u32 seq,
if (!txrate)
goto nla_put_failure;
-
- if (!(sinfo->txrate.flags & RATE_INFO_FLAGS_MCS))
- NLA_PUT_U16(msg, NL80211_RATE_INFO_LEGACY,
- sinfo->txrate.legacy);
- else
+ /* nl80211_calculate_bitrate will return 0 for mcs >= 32 */
+ NLA_PUT_U16(msg, NL80211_RATE_INFO_BITRATE,
+ nl80211_calculate_bitrate(&sinfo->txrate));
+ if (sinfo->txrate.flags & RATE_INFO_FLAGS_MCS)
NLA_PUT_U8(msg, NL80211_RATE_INFO_MCS,
sinfo->txrate.mcs);
+
if (sinfo->txrate.flags & RATE_INFO_FLAGS_40_MHZ_WIDTH)
NLA_PUT_FLAG(msg, NL80211_RATE_INFO_40_MHZ_WIDTH);
if (sinfo->txrate.flags & RATE_INFO_FLAGS_SHORT_GI)
Attachment:
signature.asc
Description: This is a digitally signed message part.
