I like what Johannes suggested, thus name for new bitrate option
changed to NL80211_RATE_INFO_BITRATE32
Patch for iw will follow shortly
Proposed patches solve issue with high bitrates not fitting into u16.
I split it into 2 patches: one introduces new u32 bitrate,
and 2-nd adds 60g specific calculations.
Idea is to report (in nl80211) both old and new values,
or only new if it not fits into u16.
User space tools encouraged to migrate to the new bitrate.
cfg80211_calculate_bitrate() changed to return u32
There are few places where cfg80211_calculate_bitrate() used
besides nl80211.c; but these places are OK with bitrate changing
from u16 to u32.
Vladimir Kondratiev (2):
{nl,cfg}80211: support high bitrates
cfg80211: bitrate calculation for 60g
include/linux/nl80211.h | 8 ++++++++
include/net/cfg80211.h | 4 +++-
net/wireless/nl80211.c | 9 +++++++--
net/wireless/util.c | 51 ++++++++++++++++++++++++++++++++++++++++++++++-
4 files changed, 68 insertions(+), 4 deletions(-)
--
1.7.9.5
60g band uses different from .11n MCS scheme, so bitrate
should be calculated differently
Signed-off-by: Vladimir Kondratiev <[email protected]>
---
include/net/cfg80211.h | 2 ++
net/wireless/util.c | 49 ++++++++++++++++++++++++++++++++++++++++++++++++
2 files changed, 51 insertions(+)
diff --git a/include/net/cfg80211.h b/include/net/cfg80211.h
index 8837efc..51f67a9 100644
--- a/include/net/cfg80211.h
+++ b/include/net/cfg80211.h
@@ -580,11 +580,13 @@ enum station_info_flags {
* @RATE_INFO_FLAGS_MCS: @tx_bitrate_mcs filled
* @RATE_INFO_FLAGS_40_MHZ_WIDTH: 40 Mhz width transmission
* @RATE_INFO_FLAGS_SHORT_GI: 400ns guard interval
+ * @RATE_INFO_FLAGS_60G: 60gHz MCS
*/
enum rate_info_flags {
RATE_INFO_FLAGS_MCS = 1<<0,
RATE_INFO_FLAGS_40_MHZ_WIDTH = 1<<1,
RATE_INFO_FLAGS_SHORT_GI = 1<<2,
+ RATE_INFO_FLAGS_60G = 1<<3,
};
/**
diff --git a/net/wireless/util.c b/net/wireless/util.c
index 6e52726..e31f1db 100644
--- a/net/wireless/util.c
+++ b/net/wireless/util.c
@@ -900,12 +900,61 @@ int cfg80211_change_iface(struct cfg80211_registered_device *rdev,
return err;
}
+static u32 cfg80211_calculate_bitrate_60g(struct rate_info *rate)
+{
+ static const u32 __mcs2bitrate[] = {
+ /* control PHY */
+ [0] = 275,
+ /* SC PHY */
+ [1] = 3850,
+ [2] = 7700,
+ [3] = 9625,
+ [4] = 11550,
+ [5] = 12512, /* 1251.25 mbps */
+ [6] = 15400,
+ [7] = 19250,
+ [8] = 23100,
+ [9] = 25025,
+ [10] = 30800,
+ [11] = 38500,
+ [12] = 46200,
+ /* OFDM PHY */
+ [13] = 6930,
+ [14] = 8662, /* 866.25 mbps */
+ [15] = 13860,
+ [16] = 17325,
+ [17] = 20790,
+ [18] = 27720,
+ [19] = 34650,
+ [20] = 41580,
+ [21] = 45045,
+ [22] = 51975,
+ [23] = 62370,
+ [24] = 67568, /* 6756.75 mbps */
+ /* LP-SC PHY */
+ [25] = 6260,
+ [26] = 8340,
+ [27] = 11120,
+ [28] = 12510,
+ [29] = 16680,
+ [30] = 22240,
+ [31] = 25030,
+ };
+
+ if (WARN_ON_ONCE(rate->mcs >= ARRAY_SIZE(__mcs2bitrate)))
+ return 0;
+
+ return __mcs2bitrate[rate->mcs];
+}
+
u32 cfg80211_calculate_bitrate(struct rate_info *rate)
{
int modulation, streams, bitrate;
if (!(rate->flags & RATE_INFO_FLAGS_MCS))
return rate->legacy;
+ if (rate->flags & RATE_INFO_FLAGS_60G)
+ return cfg80211_calculate_bitrate_60g(rate);
/* the formula below does only work for MCS values smaller than 32 */
if (WARN_ON_ONCE(rate->mcs >= 32))
--
1.7.9.5
On Thu, 2012-07-05 at 14:25 +0300, Vladimir Kondratiev wrote:
> I like what Johannes suggested, thus name for new bitrate option
> changed to NL80211_RATE_INFO_BITRATE32
>
> Patch for iw will follow shortly
>
> Proposed patches solve issue with high bitrates not fitting into u16.
>
> I split it into 2 patches: one introduces new u32 bitrate,
> and 2-nd adds 60g specific calculations.
>
> Idea is to report (in nl80211) both old and new values,
> or only new if it not fits into u16.
> User space tools encouraged to migrate to the new bitrate.
Applied, thanks. I've done a few small modifications in comments since
we can't just have userspace migrate, it needs to be compatible with
older kernels.
I'll apply the iw patches after I push this to John.
johannes
Until now, u16 value was used to represent bitrate value.
With recently introduced high bitrates, u16 becomes too small.
Thus, new 32-bit bitrate introduced.
nl80211 reports both new bitrate and old one, in case it
fits into u16. If bitrate is too high for u16, only new (32 bit)
value reported
User space tools encouraged to switch to new bitrate.
Signed-off-by: Vladimir Kondratiev <[email protected]>
---
include/linux/nl80211.h | 8 ++++++++
include/net/cfg80211.h | 2 +-
net/wireless/nl80211.c | 9 +++++++--
net/wireless/util.c | 2 +-
4 files changed, 17 insertions(+), 4 deletions(-)
diff --git a/include/linux/nl80211.h b/include/linux/nl80211.h
index 74cc55c..179bd3a 100644
--- a/include/linux/nl80211.h
+++ b/include/linux/nl80211.h
@@ -1638,12 +1638,19 @@ struct nl80211_sta_flag_update {
*
* These attribute types are used with %NL80211_STA_INFO_TXRATE
* when getting information about the bitrate of a station.
+ * There are 2 types for bitrate, legacy one that represents
+ * 16-bit value, and new one that represents 32-bit value.
+ * If rate value fits into 16 bit, both attributes reported with
+ * the same value. If rate is too high to fit into 16 bit (>6.5535Gbps),
+ * only new value included.
+ * User space tools encouraged to use new bitrate.
*
* @__NL80211_RATE_INFO_INVALID: attribute number 0 is reserved
* @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
+ * @NL80211_RATE_INFO_BITRATE32: total bitrate (u32, 100kbit/s)
* @NL80211_RATE_INFO_MAX: highest rate_info number currently defined
* @__NL80211_RATE_INFO_AFTER_LAST: internal use
*/
@@ -1653,6 +1660,7 @@ enum nl80211_rate_info {
NL80211_RATE_INFO_MCS,
NL80211_RATE_INFO_40_MHZ_WIDTH,
NL80211_RATE_INFO_SHORT_GI,
+ NL80211_RATE_INFO_BITRATE32,
/* keep last */
__NL80211_RATE_INFO_AFTER_LAST,
diff --git a/include/net/cfg80211.h b/include/net/cfg80211.h
index 0b564e8..8837efc 100644
--- a/include/net/cfg80211.h
+++ b/include/net/cfg80211.h
@@ -3487,7 +3487,7 @@ void cfg80211_ch_switch_notify(struct net_device *dev, int freq,
*
* return 0 if MCS index >= 32
*/
-u16 cfg80211_calculate_bitrate(struct rate_info *rate);
+u32 cfg80211_calculate_bitrate(struct rate_info *rate);
/* Logging, debugging and troubleshooting/diagnostic helpers. */
diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c
index 77102e6..2a5cdb6 100644
--- a/net/wireless/nl80211.c
+++ b/net/wireless/nl80211.c
@@ -2618,7 +2618,8 @@ static bool nl80211_put_sta_rate(struct sk_buff *msg, struct rate_info *info,
int attr)
{
struct nlattr *rate;
- u16 bitrate;
+ u32 bitrate;
+ u16 bitrate_compat;
rate = nla_nest_start(msg, attr);
if (!rate)
@@ -2626,8 +2627,12 @@ static bool nl80211_put_sta_rate(struct sk_buff *msg, struct rate_info *info,
/* cfg80211_calculate_bitrate will return 0 for mcs >= 32 */
bitrate = cfg80211_calculate_bitrate(info);
+ /* report 16-bit bitrate only if we can */
+ bitrate_compat = bitrate < (1UL << 16) ? bitrate : 0;
if ((bitrate > 0 &&
- nla_put_u16(msg, NL80211_RATE_INFO_BITRATE, bitrate)) ||
+ nla_put_u32(msg, NL80211_RATE_INFO_BITRATE32, bitrate)) ||
+ (bitrate_compat > 0 &&
+ nla_put_u16(msg, NL80211_RATE_INFO_BITRATE, bitrate_compat)) ||
((info->flags & RATE_INFO_FLAGS_MCS) &&
nla_put_u8(msg, NL80211_RATE_INFO_MCS, info->mcs)) ||
((info->flags & RATE_INFO_FLAGS_40_MHZ_WIDTH) &&
diff --git a/net/wireless/util.c b/net/wireless/util.c
index 0228c64..6e52726 100644
--- a/net/wireless/util.c
+++ b/net/wireless/util.c
@@ -900,7 +900,7 @@ int cfg80211_change_iface(struct cfg80211_registered_device *rdev,
return err;
}
-u16 cfg80211_calculate_bitrate(struct rate_info *rate)
+u32 cfg80211_calculate_bitrate(struct rate_info *rate)
{
int modulation, streams, bitrate;
--
1.7.9.5