2020-10-29 18:38:53

by Jouni Malinen

[permalink] [raw]
Subject: [PATCH] cfg80211: Add support to calculate and report 4096-QAM HE rates

From: Vamsi Krishna <[email protected]>

Drivers supporting 4096-QAM rates as a vendor extension in HE mode need
to update the correct rate info to userspace while using 4096-QAM (MCS12
and MCS13) in HE mode. Add support to calculate bitrates of HE-MCS12 and
HE-MCS13 which represent the 4096-QAM modulation schemes. The MCS12 and
MCS13 bitrates are defined in IEEE P802.11be/D0.1.

In addition, scale up the bitrates by 3*2048 in order to accommodate
calculations for the new MCS12 and MCS13 rates without losing fraction
values.

Signed-off-by: Vamsi Krishna <[email protected]>
Signed-off-by: Jouni Malinen <[email protected]>
---
net/wireless/util.c | 32 +++++++++++++++++---------------
1 file changed, 17 insertions(+), 15 deletions(-)

diff --git a/net/wireless/util.c b/net/wireless/util.c
index f01746894a4e..5b6c80ae564a 100644
--- a/net/wireless/util.c
+++ b/net/wireless/util.c
@@ -1276,20 +1276,22 @@ static u32 cfg80211_calculate_bitrate_vht(struct rate_info *rate)

static u32 cfg80211_calculate_bitrate_he(struct rate_info *rate)
{
-#define SCALE 2048
- u16 mcs_divisors[12] = {
- 34133, /* 16.666666... */
- 17067, /* 8.333333... */
- 11378, /* 5.555555... */
- 8533, /* 4.166666... */
- 5689, /* 2.777777... */
- 4267, /* 2.083333... */
- 3923, /* 1.851851... */
- 3413, /* 1.666666... */
- 2844, /* 1.388888... */
- 2560, /* 1.250000... */
- 2276, /* 1.111111... */
- 2048, /* 1.000000... */
+#define SCALE 6144
+ u32 mcs_divisors[14] = {
+ 102399, /* 16.666666... */
+ 51201, /* 8.333333... */
+ 34134, /* 5.555555... */
+ 25599, /* 4.166666... */
+ 17067, /* 2.777777... */
+ 12801, /* 2.083333... */
+ 11769, /* 1.851851... */
+ 10239, /* 1.666666... */
+ 8532, /* 1.388888... */
+ 7680, /* 1.250000... */
+ 6828, /* 1.111111... */
+ 6144, /* 1.000000... */
+ 5690, /* 0.926106... */
+ 5120, /* 0.833333... */
};
u32 rates_160M[3] = { 960777777, 907400000, 816666666 };
u32 rates_969[3] = { 480388888, 453700000, 408333333 };
@@ -1301,7 +1303,7 @@ static u32 cfg80211_calculate_bitrate_he(struct rate_info *rate)
u64 tmp;
u32 result;

- if (WARN_ON_ONCE(rate->mcs > 11))
+ if (WARN_ON_ONCE(rate->mcs > 13))
return 0;

if (WARN_ON_ONCE(rate->he_gi > NL80211_RATE_INFO_HE_GI_3_2))
--
2.20.1