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>

This will allow to get sniffer captures with correct
settings for these HT / VHT capabilities.
Also set the corresponding HAVE_MCS / VHT_KNOWN bits in
the registration to mac80211.
Reviewed-by: NJohannes Berg <johannes.berg@intel.com>
Signed-off-by: NEmmanuel Grumbach <emmanuel.grumbach@intel.com>

The current WARNING isn't very helpful.
Reported-by: NDavid Binderman <dcb314@hotmail.com>
Signed-off-by: NEmmanuel Grumbach <emmanuel.grumbach@intel.com>

There's not a single rate control algorithm actually in
a separate module where the module refcount would be
required. Similarly, there's no specific rate control
module.

Therefore, all the module handling code in rate control
is really just dead code, so remove it.
Signed-off-by: NJohannes 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: NJohannes Berg <johannes.berg@intel.com>

This makes the code a little bit longer as zero-extension
has to be done (mov vs. movzwl), but that's miniscule and
the space saving is significant, about 600 bytes in DVM
and 700 bytes in MVM, so the cache effect should be worth
the few bytes more code.

While at it, remove two spurious blank lines in variable
declaration blocks.
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>
Reviewed-by: NEyal Shapira <eyal@wizery.com>
Signed-off-by: NEmmanuel Grumbach <emmanuel.grumbach@intel.com>

Discovered by klocwork

Array 'iwl_rate_mcs' of size 15 may use index value(s) -1
  * rs.c:2562: index = iwl_hwrate_to_plcp_idx(rate)
    * rs.c:2562: Result of function call 'iwl_hwrate_to_plcp_idx(rate)' is '[-1,14]'
  * rs.c:2565: Array 'iwl_rate_mcs' size is 15.
  * rs.c:2565: Possible attempt to access element -1 of array 'iwl_rate_mcs'.

While at it stop using index = -1 and always use IWL_RATE_INVALID
Signed-off-by: NEyal Shapira <eyalx.shapira@intel.com>
Signed-off-by: NEmmanuel Grumbach <emmanuel.grumbach@intel.com>

If we can't switch to a column because no rates are supported
in that column this led to a state where the search cycle
got stuck and never ended. This in turn also led to aggregation
not being turned on. Fix this by marking a column as
visited if we can't switch to it.
Reported-and-tested-by: NKarl Beldan <karl.beldan@gmail.com>
Signed-off-by: NEyal Shapira <eyal@wizery.com>
Signed-off-by: NEmmanuel Grumbach <emmanuel.grumbach@intel.com>

None of these files are actually using any __init type directives
and hence don't need to include <linux/init.h>.  Most are just a
left over from __devinit and __cpuinit removal, or simply due to
code getting copied from one driver to the next.
Signed-off-by: NPaul Gortmaker <paul.gortmaker@windriver.com>
Acked-by: NLarry Finger <Larry.Finger@lwfinger.net>
Acked-by: NChristian Lamparter <chunkeey@googlemail.com>
Acked-by: NGertjan van Wingerde <gwingerde@gmail.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Happy new year!
Signed-off-by: NEmmanuel Grumbach <emmanuel.grumbach@intel.com>

Found by klocwork analysis.
mvm could be NULL which may cause a NULL dereference
in a theoretical call flow

rs_fill_lq_cmd(mvm = NULL, ...)
rs_build_rates_table
rs_fill_rates_for_column
ucode_rate_from_rs_rate
IWL_ERR(mvm,...)

No real reason for passing NULL to rs_fill_lq_cmd so fix that.
Reported-by: NEytan Lifshitz <eytan.lifshitz@intel.com>
Signed-off-by: NEyal Shapira <eyal@wizery.com>
Signed-off-by: NEmmanuel Grumbach <emmanuel.grumbach@intel.com>

Don't check if mvm->fw->cs is NULL since it can't be.
cs is an array member of iwl_fw, it can't be NULL.

Use memset(ptr, 0, sizeof(*ptr)); instead of
memset(ptr, 0, sizeof(struct ptr_type));
Signed-off-by: NEmmanuel Grumbach <emmanuel.grumbach@intel.com>

Signed-off-by: NJohannes Berg <johannes.berg@intel.com>
Reviewed-by: NEyalX Shapira <eyal@wizery.com>
Signed-off-by: NEmmanuel Grumbach <emmanuel.grumbach@intel.com>

MCS9 introduces some corner cases in the current rs
algorithm which may lead to non optimal throughput and
instability in the throughput. Until all the corner
cases are resolved disable MCS9 for Tx as a workaround
which yields better throughput results as MCS8 is much
more stable.
Signed-off-by: NEyal Shapira <eyal@wizery.com>
Signed-off-by: NEmmanuel Grumbach <emmanuel.grumbach@intel.com>

Extract the scale action decision to a different function
in preparation of modifying it. While at it also convert
the scale action values from hardcoded values to a clear enum.
Signed-off-by: NEyal Shapira <eyal@wizery.com>
Signed-off-by: NEmmanuel Grumbach <emmanuel.grumbach@intel.com>

The logs are emitted in a flow in which there were retries
and the rates in the rate table entry didn't match the active
or search table. This doesn't indicate a problem and is
expected in most cases where there will be retries for some
reason. Remove the logs.
Signed-off-by: NEyal Shapira <eyal@wizery.com>
Signed-off-by: NEmmanuel Grumbach <emmanuel.grumbach@intel.com>

The new logic will attempt more rates with less retries
per rate. Also when starting off with MIMO it will
fallback to SISO with the same MCS and only then to Legacy.
Previously we fell back directly to Legacy.
Signed-off-by: NEyal Shapira <eyal@wizery.com>
Signed-off-by: NEmmanuel Grumbach <emmanuel.grumbach@intel.com>

The supported legacy rate mask is initialized when rs
is initialized based on the remote peer supported rates.
There's no need to re mask it repeatedly with the supported
remote peer rates.
Signed-off-by: NEyal Shapira <eyal@wizery.com>
Signed-off-by: NEmmanuel Grumbach <emmanuel.grumbach@intel.com>