The variable 'tid' is already defined in this function, so use
just 't' for the new one. As we return from the function just
overwriting 'tid' would be acceptable, but less obvious to the
reader.
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>
Signed-off-by: NEmmanuel Grumbach <emmanuel.grumbach@intel.com>

STBC is enabled on HT/VHT SISO rates in case we don't care
about power consumption and it won't hurt BT.
This is done only in case the peer and our chip support STBC
of course.
While at it fixed a bug which was causing bw and ldpc
flags to be set incorrectly in the rate scale table in case
we are switching to a legacy Tx column. This had no real impact.
Signed-off-by: NEyal Shapira <eyalx.shapira@intel.com>
Signed-off-by: NEmmanuel Grumbach <emmanuel.grumbach@intel.com>

mac80211 will never call rate_control_tx_status with a NULL
pointer for sta. Remove the superfluous check. This check
misled smatch.
Signed-off-by: NEmmanuel Grumbach <emmanuel.grumbach@intel.com>

The current TLC isn't optimized for low latency and some devices
have issues with MIMO. This kind of combo creates latency issues.
Allow to temporarily disable MIMO for tests in order to solve
the latency issues without the added complexity of MIMO.
Signed-off-by: NEyal Shapira <eyalx.shapira@intel.com>
Signed-off-by: NArik Nemtsov <arikx.nemtsov@intel.com>
Signed-off-by: NEmmanuel Grumbach <emmanuel.grumbach@intel.com>

In case of traffic on multiple TIDs where one is aggregated
and the other is not RS would toggle between considering
traffic vs. the station as aggregated and not aggregated.
Instead consider the sta state as aggregated as long as
there's at least one TID aggregated.
This limitation is because the rates table is kept per
station and not per TID.
Signed-off-by: NEyal Shapira <eyalx.shapira@intel.com>
Signed-off-by: NEmmanuel Grumbach <emmanuel.grumbach@intel.com>

Enable RS to get updated directly via iwl_mvm_rs_tx_status
which will be called by the driver and not via mac80211
rate control. This is required for a following patch to
report on BAs which do not cause the BA window to progress.
Also this is a first step in decoupling rs from the
mac80211 rate control.
Signed-off-by: NEyal Shapira <eyalx.shapira@intel.com>
Signed-off-by: NEmmanuel Grumbach <emmanuel.grumbach@intel.com>

Improve the initial tx rate and antenna selection to be based on
the rssi of the last rx. This avoids starting at the lowest legacy
rate always and requiring more tx traffic to "climb" up the rates.
Since this option might cause trouble in certain setups, allow to
disable it by default.
Signed-off-by: NEyal Shapira <eyalx.shapira@intel.com>
Reviewed-by: NJohannes Berg <johannes.berg@intel.com>
Signed-off-by: NEmmanuel Grumbach <emmanuel.grumbach@intel.com>

Move the tx stats to the persistent area of lq_sta to
avoid them being zeroed out every time rs reinitializes
which happens after tx idle for 5 secs for example.
The automatic zeroing out made them difficult to use.
Signed-off-by: NEyal Shapira <eyalx.shapira@intel.com>
Reviewed-by: NJohannes Berg <johannes.berg@intel.com>
Signed-off-by: NEmmanuel Grumbach <emmanuel.grumbach@intel.com>

max_rate_idx constraint is deprecated and it's handling is
faulty as well as it is relevant only for legacy rates but
was considered in HT/VHT. In most cases there was no side effect
as max_rate_idx was set to -1 but in certain cases like P2P
it got set to an actual rate idx which would limit the maximum
rate in HT/VHT by mistake.
max_rate_idx should be replaced by the masks fields but for
now remove it.
Signed-off-by: NEyal Shapira <eyalx.shapira@intel.com>
Reviewed-by: NJohannes Berg <johannes.berg@intel.com>
Signed-off-by: NEmmanuel Grumbach <emmanuel.grumbach@intel.com>

Use LDPC for Tx and publish support for Rx in case the chip
supports LDPC. Enable it for the 7265 family.
Signed-off-by: NEyal Shapira <eyalx.shapira@intel.com>
Reviewed-by: NJohannes Berg <johannes.berg@intel.com>
Signed-off-by: NEmmanuel Grumbach <emmanuel.grumbach@intel.com>

Our legal structure changed at some point (see wikipedia), but
we forgot to immediately switch over to the new copyright
notice.

For files that we have modified in the time since the change,
add the proper copyright notice now.
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>
Signed-off-by: NEmmanuel Grumbach <emmanuel.grumbach@intel.com>

Aggregations hit latency so disable it by default on
low latency vifs for now. Enable control over this behavior and
allow control over the max frames in an AMPDU in low latency
vifs via debugfs.
Signed-off-by: NEyal Shapira <eyalx.shapira@intel.com>
Reviewed-by: NJohannes Berg <johannes.berg@intel.com>
Signed-off-by: NEmmanuel Grumbach <emmanuel.grumbach@intel.com>

Performance is less an issue in P2P and reliability
is critical. Enable protection always for P2P.
Signed-off-by: NEmmanuel Grumbach <emmanuel.grumbach@intel.com>

This allows to leave a frame in the Tx Fifo which allows
the firmware to try to enter burst mode.
The end result of this is a better latency since the
firmware utilises the TxOP better.

Also limit the AMPDU size to the limit set in the ADDBA
response. This doesn't change much since the AMPDU size
was limited by the configuration of the hardware scheduler,
but here we add a software limit by the mean of the link
quality command.
Reviewed-by: NJohannes Berg <johannes.berg@intel.com>
Signed-off-by: NEmmanuel Grumbach <emmanuel.grumbach@intel.com>

These file are removed recursively anyway, so there's no
point saving them just to redundantly remove them later.
Signed-off-by: NEliad Peller <eliadx.peller@intel.com>
Signed-off-by: NEmmanuel Grumbach <emmanuel.grumbach@intel.com>

iwl_mvm_rs_rate_init() is called multiple times to re-init
the rate scaling statistics (e.g. after some idle time).

It clears all the lq_sta sta, including some fields that
shouldn't be cleared (e.g. debugfs pointers). Fix it
by adding a new 'persistent' sub-struct, and
avoid clearing it on (re-)init.

Move the initialization of the persistent fields to
rs_alloc_sta instead.
Signed-off-by: NEliad Peller <eliadx.peller@intel.com>
Reviewed-by: NJohannes Berg <johannes.berg@intel.com>
Signed-off-by: NEmmanuel Grumbach <emmanuel.grumbach@intel.com>

All messages should have a trailing newline, add all the
missing ones. Also make all messages constants, replacing
the single one that pointlessly used a variable.
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>
Signed-off-by: NEmmanuel Grumbach <emmanuel.grumbach@intel.com>

After fixes to the rs algorithm reenable MCS9.
Signed-off-by: NEyal Shapira <eyalx.shapira@intel.com>
Reviewed-by: NJohannes Berg <johannes.berg@intel.com>
Signed-off-by: NEmmanuel Grumbach <emmanuel.grumbach@intel.com>

The expected throughput table used when estimating a new column
depends on the channel bandwidth. When switching from legacy to
siso or mimo the wrong expected throughput table was used as it
was chosen based on the the channel bandwidth in legacy which is
always 20Mhz. Instead it should be chosen based on the current sta
bandwidth which could be also 40Mhz or 80Mhz.
When enabling MCS9 this bug leads to a problem where the max
expected throughput of the siso or mimo column is 0 as MCS9 isn't
supported in 20Mhz. This in turns prevents switching to siso or mimo.

Fix this by using the sta bandwidth when deciding which table to choose.
Signed-off-by: NEyal Shapira <eyalx.shapira@intel.com>
Signed-off-by: NEmmanuel Grumbach <emmanuel.grumbach@intel.com>

TPC is a power optimization which should only be attempted when
we're in the "stay in column" state after we've locked onto an optimal
rate.
Signed-off-by: NEyal Shapira <eyalx.shapira@intel.com>
Reviewed-by: NEliad Peller <eliad@wizery.com>
Signed-off-by: NEmmanuel Grumbach <emmanuel.grumbach@intel.com>

Currently we were checking only if the driver power_scheme is set
to CAM. TPC shouldn't be enabled also when disabling powersave on the
interface (e.g. iw wlan0 set power_save off)
which may occur even if power_scheme wasn't set to CAM.
Signed-off-by: NEyal Shapira <eyalx.shapira@intel.com>
Reviewed-by: NEliad Peller <eliad@wizery.com>
Signed-off-by: NEmmanuel Grumbach <emmanuel.grumbach@intel.com>

rs_get_best_rate determines the optimal rate to try in a
new Tx column. Currently we were sometimes trying a too high
rate which would lead us to fail and avoid switching to the
new column despite it having a potential to be better.
Change the logic to try and find the first rate which would
exceed the current actual throughput or be more aggressive
if the success ratio is good.
Signed-off-by: NEyal Shapira <eyalx.shapira@intel.com>
Signed-off-by: NEmmanuel Grumbach <emmanuel.grumbach@intel.com>

Adding more options in the search cycle causes longer
search cycles with additional wondering off to non optimal Tx
configurations. Reduce the Tx configurations searched to
improve throughput in non optimal attenuations.
Signed-off-by: NEyal Shapira <eyalx.shapira@intel.com>
Signed-off-by: NEmmanuel Grumbach <emmanuel.grumbach@intel.com>

My bad - I forgot to update this when sending the patch
upstream.

Fixes: 87d5e415 ("iwlwifi: mvm: rs: reinit rs if no tx for a long time")
Signed-off-by: NEmmanuel Grumbach <emmanuel.grumbach@intel.com>

The per rate stats should be cleared when aggregation state changes
to avoid making rate scale decisions based on throughput figures which
were collected prior to the aggregation state change and are now stale.
While at it make sure any clearing of the per rate stats will get logged.

Cc: <stable@vger.kernel.org> [3.14]
Signed-off-by: NEyal Shapira <eyalx.shapira@intel.com>
Signed-off-by: NEmmanuel Grumbach <emmanuel.grumbach@intel.com>

Don't search columns which are unlikely to succeed as previous
columns searched with less aggressive modulation failed.

Cc: <stable@vger.kernel.org> [3.14]
Signed-off-by: NEyal Shapira <eyalx.shapira@intel.com>
Signed-off-by: NEmmanuel Grumbach <emmanuel.grumbach@intel.com>

Allow switching back to legacy Tx columns so we'll stop doing
HT/VHT in case we're far from the AP. Stop active aggregation when
making a deciding to stay in a legacy column.
Despite having low legacy rates in the LQ table lower entries
it doesn't help much in case we're doing aggregations as the
aggregation was being transmitted in the initial rate of the table.

This should help traffic stalls when far from the AP.

Cc: <stable@vger.kernel.org> [3.14]
Signed-off-by: NEyal Shapira <eyalx.shapira@intel.com>
Signed-off-by: NEmmanuel Grumbach <emmanuel.grumbach@intel.com>

After being idle for a long time (>5sec) the rs statistics
will be stale so we prefer to reset rs and start from legacy
rates again. This gives better results when the attenuation
increased signficantly (e.g. we got further from the AP) and
after a while we start Tx
Note that the first Tx after the idle period will still go out
in the old modulation and rate but this seemed a simpler approach
compared to adding a timer or modifying mac80211 for this.
The negative impact is negligble as we'll recover quickly.

Cc: <stable@vger.kernel.org> [3.14]
Signed-off-by: NEyal Shapira <eyalx.shapira@intel.com>
Signed-off-by: NEmmanuel Grumbach <emmanuel.grumbach@intel.com>

Change the down/upscale decision logic a bit to be based
on different success ratio thresholds. This fixes the implementation
compared to the rate scale algorithm which was planned to yield
optimal results. Also fix a case where a lower rate wasn't explored
despite being a potential for better throughput.
While at it rewrite rs_get_rate_action to be more clear and clean.

Cc: <stable@vger.kernel.org> [3.14]
Signed-off-by: NEyal Shapira <eyalx.shapira@intel.com>
Signed-off-by: NEmmanuel Grumbach <emmanuel.grumbach@intel.com>

The selection of the max expected throughput for a column
didn't take into account the maximal allowed rate for the current
peer. This can cause unnecessary switches during the search cycle
to columns which have no chance of beating the current throughput.
Signed-off-by: NEyal Shapira <eyalx.shapira@intel.com>
Signed-off-by: NEmmanuel Grumbach <emmanuel.grumbach@intel.com>

Collect accumulated stats of tx attempts and successes
per rate and column for debugging purposes.
These stats can be read via debugfs file drv_tx_stats
and can also be reset by writing to this file.
Signed-off-by: NEyal Shapira <eyalx.shapira@intel.com>
Signed-off-by: NEmmanuel Grumbach <emmanuel.grumbach@intel.com>

Allow fixing the tx power reduction through debugfs
file.

The change doesn't take affect immediately, but
will be considered the next time tpc is evaluated.
Signed-off-by: NEliad Peller <eliadx.peller@intel.com>
Signed-off-by: NEmmanuel Grumbach <emmanuel.grumbach@intel.com>

Implement Adaptive Tx Power Control algorithm.

ATPC basically tries to decrease the tx power
as much as possible while the throughput is
not being hurt.
Signed-off-by: NEliad Peller <eliadx.peller@intel.com>
Reviewed-by: NJohannes Berg <johannes.berg@intel.com>
Signed-off-by: NEmmanuel Grumbach <emmanuel.grumbach@intel.com>

mimo_delim was always set to 0 instead of pointing to
the first SISO entry after MIMO rates.
This can cause keep transmitting in MIMO even when we shouldn't.
For example when the peer is requesting static SMPS.

Cc: <stable@vger.kernel.org> [3.14]
Signed-off-by: NEyal Shapira <eyalx.shapira@intel.com>
Signed-off-by: NEmmanuel Grumbach <emmanuel.grumbach@intel.com>

instead of duplicating the same loop multiple times,
use a new function for it.

this will be later used also for clearing other
windows in the table.
Signed-off-by: NEliad Peller <eliadx.peller@intel.com>
Signed-off-by: NEmmanuel Grumbach <emmanuel.grumbach@intel.com>

Make _rs_collect_tx_data get window as param, in order
to be able to set various windows.

This will be used later for saving tpc statistics
as well.
Signed-off-by: NEliad Peller <eliadx.peller@intel.com>
Signed-off-by: NEmmanuel Grumbach <emmanuel.grumbach@intel.com>

We should explore all possible columns when searching to be
as resilient as possible to changing conditions. This fixes
for example a scenario where even after a sudden creation of
rssi difference between the 2 antennas we would keep doing MIMO
at a low rate instead of switching to SISO at a higher rate using
the better antenna which was the optimal configuration.
Signed-off-by: NEyal Shapira <eyalx.shapira@intel.com>
Signed-off-by: NEmmanuel Grumbach <emmanuel.grumbach@intel.com>

Make bt-coex generic to allow other coex mechanisms.
Signed-off-by: NEmmanuel Grumbach <emmanuel.grumbach@intel.com>

Collect statistics regarding rates and aggregations in Rx
frames and export the data via debugfs.
Signed-off-by: NEyal Shapira <eyalx.shapira@intel.com>
Signed-off-by: NEmmanuel Grumbach <emmanuel.grumbach@intel.com>

These inlines are pretty pointless now as they just return a
fixed struct value, remove them - the code even gets shorter.
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>
Reviewed-by: NEran Harary <eran.harary@intel.com>
Signed-off-by: NEmmanuel Grumbach <emmanuel.grumbach@intel.com>