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: Thomas Huehn <thomas@net.t-labs.tu-berlin.de>
Tested-by: Stefan Venz <ikstream86@gmail.com>
Acked-by: Felix Fietkau <nbd@openwrt.org>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Add get_expected_throughput() API to mac80211 so that each
driver can implement its own version based on the RC
algorithm they are using (might be using an HW RC algo).
The API returns a value expressed in Kbps.
Also, add the new get_expected_throughput() member
to the rate_control_ops structure in order to be
able to query the RC algorithm (this patch provides an
implementation of this API for both minstrel and
minstrel_ht).
The related member in the station_info object is now
filled accordingly when dumping a station.
Cc: Felix Fietkau <nbd@openwrt.org>
Signed-off-by: Antonio Quartulli <antonio@open-mesh.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Antonio and I were looking over this code and some things
didn't immediately make sense, so we came up with two small
clarifications.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
The sample table is initialized only once at module start, so
is really __read_mostly. Additionally, the code to init it can
be marked __init since it will never be needed again, it is
likely automatically inlined into the __init function already
by the compiler, so this doesn't really make a difference.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Change the code to allow making all the rate control ops
const, nothing ever needs to change them. Also change all
drivers to make use of this and mark the ops const.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
ATM minstrel_ht does not check whether a sampling rate is supported.
Unsupported rates attempts can trigger when there are holes in bitfields
of supported MCSes belonging to the same group (e.g many devices are
MCS32 capable without MCS33->39 capable, also we systematically have a
hole for CCK rates).
Drop any attempts to sample unsupported rates, as suggested by Felix.
This is not a problem in minstrel which fills a per STA sample table
with only supported rates (though only at init).
Signed-off-by: Karl Beldan <karl.beldan@rivierawaves.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
ATM, only the first array value returned by get_random_bytes is used.
This change moves the call to get_random_bytes from the nested loop it
is in to its parent.
While at it, replace get_random_bytes with prandom_bytes since PRNs are
way enough for the selection process.
After this, minstrel_ht reclaims 80 PR-bytes instead of 640 R-bytes.
minstrels use sample tables to probe different rates in a randomized
manner.
minstrel_ht inits one single sample table upon registration (during
subsys_initcalls) and minstrel uses one per STA addition in minstrel.
Signed-off-by: Karl Beldan <karl.beldan@rivierawaves.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Consecutive MCSes in [8*(NSS-1)->8*NSS[ have the same number NSS of
streams (except for MCS32 which is mishandled ATM).
ATM minstrel_ht uses MCS_GROUP_RATES in place of this 8 modulus.
This change replaces such occurences and by doing so allows for different
values of MCS_GROUP_RATES (e.g to cope with VHT MCS8,9).
Signed-off-by: Karl Beldan <karl.beldan@rivierawaves.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Commit 3e8b1eb "mac80211/minstrel_ht: improve rate selection stability"
introduced a local capped prob in minstrel_ht_calc_tp but omitted to use
it to compute the per rate throughput.
Signed-off-by: Karl Beldan <karl.beldan@rivierawaves.com>
Cc: Felix Fietkau <nbd@openwrt.org>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
When initializing rates selections starting indexes upon stats update,
the minstrel_sta->max_* rates should be 'group * MCS_GROUP_RATES + i'
not 'i'. This affects settings where one of the peers does not support
any of the rates of the group 0 (i.e. when ht_cap.mcs.rx_mask[0] == 0).
Signed-off-by: Karl Beldan <karl.beldan@rivierawaves.com>
Acked-by: Felix Fietkau <nbd@openwrt.org>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Do not override max_tp_rate, max_tp_rate2 and max_prob_rate configured
according to fixed_rate in minstrel_ht_update_stats throughput computation
Signed-off-by: Lorenzo Bianconi <lorenzo.bianconi83@gmail.com>
Acked-by: Felix Fietkau <nbd@openwrt.org>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Sujith reports that my commit af61a16518
("mac80211: add control port protocol TX control flag") broke ath9k
(aggregation). The reason is that I made minstrel_ht use the flag in
the TX status path, where it can have been overwritten by the driver.
Since we have no more space in info->flags, revert that part of the
change for now, until we can reshuffle the flags or so.
Reported-by: Sujith Manoharan <c_manoha@qca.qualcomm.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
brcm80211 cannot handle sending frames with CCK rates as part of an
A-MPDU session. Other drivers may have issues too. Set the flag in all
drivers that have been tested with CCK rates.
This fixes a reported brcmsmac regression introduced in
commit ef47a5e4f1aaf1d0e2e6875e34b2c9595897bef6
"mac80211/minstrel_ht: fix cck rate sampling"
Cc: stable@vger.kernel.org # 3.10
Reported-by: Tom Gundersen <teg@jklm.no>
Signed-off-by: Felix Fietkau <nbd@openwrt.org>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
A lot of drivers check the frame protocol for ETH_P_PAE,
for various reasons (like making those more reliable).
Add a new flags bitmap to the TX control info and a new
flag indicating the control port protocol is in use to
let all drivers also apply such logic to other control
port protocols, should they be configured.
Also use the new flag in the iwlwifi drivers.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
The CCK group needs special treatment to set the right flags and rate
index. Add this missing check to prevent setting broken rates for tx
packets.
Cc: stable@vger.kernel.org # 3.10
Signed-off-by: Felix Fietkau <nbd@openwrt.org>
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
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: Felix Fietkau <nbd@openwrt.org>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Initialize {mp,mi}->{max_tp_rate,max_tp_rate2,max_prob_rate} in
minstrel_ht's rate_init and rate_update.
Signed-off-by: Karl Beldan <karl.beldan@rivierawaves.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Thomas Huehn
Antonio Quartulli
Johannes Berg
Weilong Chen
John W. Linville
Karl Beldan
Lorenzo Bianconi
Felix Fietkau
Simon Wunderlich