Since 5935839a ("mac80211: improve minstrel_ht rate sorting by
throughput & probability"), the rate indexes are manipulated via u8's
and hence allow for a maximum of 256 mcs_group entries in
minstrel_mcs_groups.

ATM, minstrel_ht advertizes support up to 3HTSS@40MHz, consuming:
8(MCS_GROUP_RATES) * (3(SS)*2(GI)*2(BW)+1(CCK)), i.e. 104 entries.

Support for 3VHTSS@80MHz will require:
10(MCS_GROUP_RATES) * (3(SS)*2(GI)*2(BW)+1(CCK)) +
10(MCS_GROUP_RATES) * (3(SS)*2(GI)*3(BW)), i.e. 130 + 180 entries.

This change moves from u8s to u16s where necessary.
Signed-off-by: NKarl Beldan <karl.beldan@rivierawaves.com>
Cc: Felix Fietkau <nbd@openwrt.org>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

This patch improves the way minstrel_ht sorts rates according to throughput
and success probability. 3 FOR-loops across the entire rate and mcs group set
in function minstrel_ht_update_stats() which where used to determine the
fastest, second fastest and most robust rate are reduced to 2 FOR-loop.

The sorted list of rates according throughput is extended to the best four
rates as we need them in upcoming joint rate and power control. The sorting
is done via the new function minstrel_ht_sort_best_tp_rates(). The annotation
of those 4 best throughput rates in the debugfs file rc-stats is changes to:
"A,B,C,D", where A is the fastest rate and C the 4th fastest.
Signed-off-by: NThomas Huehn <thomas@net.t-labs.tu-berlin.de>
Tested-by: NStefan Venz <ikstream86@gmail.com>
Acked-by: NFelix Fietkau <nbd@openwrt.org>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

Minstrel and Mintrel_HT used there own structs to keep track of rate
statistics. Unify those variables in struct minstrel_rate_states and
move it to rc80211_minstrel.h for common usage. This is a clean-up
patch to prepare Minstrel and Minstrel_HT codebase for upcoming TPC.
Signed-off-by: NThomas Huehn <thomas@net.t-labs.tu-berlin.de>
Acked-by: NFelix Fietkau <nbd@openwrt.org>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

Pass the rate selection table to mac80211 from minstrel_ht_update_stats.
Only rates for sample attempts are set in info->control.rates.
Signed-off-by: NFelix Fietkau <nbd@openwrt.org>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

Both minstrel versions use individual ways to scale up integer values
to perform calculations. Merge minstrel_ht's scaling macros into
minstrels header file and use them in both minstrel versions.
Acked-by: NFelix Fietkau <nbd@openwrt.org>
Signed-off-by: NThomas Huehn <thomas@net.t-labs.tu-berlin.de>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

If a rate is below the max_tp_rate, sample it frequently if:
- it is above max_tp_rate2, or
- it is above max_prob_rate and is a candidate for max_prob_rate
  (has fewer streams than max_tp_rate).
This helps the retry chain recover more quickly from bad statistics
caused by collisions or interference, and slightly reduces throughput
fluctuations with higher rates.
Signed-off-by: NFelix Fietkau <nbd@openwrt.org>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

When MCS rates start to get bad in 2.4 GHz because of long range or
strong interference, CCK rates can be a lot more robust.

This patch adds a pseudo MCS group containing CCK rates (long preamble
in the lower 4 slots, short preamble in the upper slots).
Signed-off-by: NFelix Fietkau <nbd@openwrt.org>
[make minstrel_ht_get_stats static]
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>
Acked-by: NFelix Fietkau <nbd@openwrt.org>

Signed-off-by: NFelix Fietkau <nbd@openwrt.org>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>