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>

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>

Simplify the code a bit more by extracting the rates table
building logic into a separate function and handle setting
a fixed rate for debug in a separate flow.
Also avoid using and saving ucode rate format in different
places. Instead use rs_rate struct and convert to ucode format
only when filling the rates table in the LQ command.
Signed-off-by: NEyal Shapira <eyal@wizery.com>
Signed-off-by: NEmmanuel Grumbach <emmanuel.grumbach@intel.com>

Move rs_program_fix_rate right before it's caller where we're
already in the context of an ifdef CPTCFG_MAC80211_DEBUGFS so
we can get rid of the extra ifdefs surrounding the original
location.
Signed-off-by: NEyal Shapira <eyal@wizery.com>
Signed-off-by: NEmmanuel Grumbach <emmanuel.grumbach@intel.com>

This fixes compilation issues with CONFIG_MAC80211_DEBUGFS
not enabled.
Signed-off-by: NEmmanuel Grumbach <emmanuel.grumbach@intel.com>

Rewrite the search cycle state machine to use a more data
oriented approach where the different Tx columns (configs)
limitations and next columns to search are reprsented in
tables which are easy to change. This overhaul also includes
several major fixes:

1. Prevent going back to a specific Tx column in a search
cycle if it was already explored.

2. Avoid switching to a Tx column that doesn't have any chance
if it performs perfectly to beat the current throughput we're
getting.

These issues were degrading throughput as they were causing
switching to "bad" Tx columns.
Signed-off-by: NEyal Shapira <eyal@wizery.com>
Signed-off-by: NEmmanuel Grumbach <emmanuel.grumbach@intel.com>

Use the 20Mhz channel width define instead of just the number
zero for legacy rates. Note that the define has the same value
so this is just a minor cleanup.
Signed-off-by: NEyal Shapira <eyal@wizery.com>
Signed-off-by: NEmmanuel Grumbach <emmanuel.grumbach@intel.com>

The table rs_ht_to_legacy is used to get the next legacy rate
following the last HT or VHT rate in the LQ rates table.
The mapping wasn't correct as well as didn't include entries
for MCS8/9 which led to out of bounds access. This didn't
trigger a crash but led to legacy rate entries using 1Mbps
rate.
In 5Ghz this probably caused the Tx to fail completely given
that Tx attempt would have reached the legacy entries and 1Mbps
isn't valid.
Signed-off-by: NEyal Shapira <eyal@wizery.com>
Signed-off-by: NEmmanuel Grumbach <emmanuel.grumbach@intel.com>

Drop code which was relevant when there were chips with
3 antennas. Setting to ANT_AB should be ok with all mvm
supported chips.
Signed-off-by: NEyal Shapira <eyal@wizery.com>
Signed-off-by: NEmmanuel Grumbach <emmanuel.grumbach@intel.com>

No use of the ieee80211 header. Drop it.
Signed-off-by: NEyal Shapira <eyal@wizery.com>
Signed-off-by: NEmmanuel Grumbach <emmanuel.grumbach@intel.com>

Introduce rs_rate which represents a rate. Use this structure
instead of iwl_scale_tbl_info where we're dealing with a single
rate.
This avoids allocating the big iwl_scale_tbl_info structure
on the stack in several cases like converting to ucode rate
format or from ucode rate format.
Signed-off-by: NEyal Shapira <eyal@wizery.com>
Signed-off-by: NEmmanuel Grumbach <emmanuel.grumbach@intel.com>

Remove this as it's unused.
Signed-off-by: NEyal Shapira <eyal@wizery.com>
Signed-off-by: NEmmanuel Grumbach <emmanuel.grumbach@intel.com>

Remain in the same Tx modulation (i.e. column) for a longer
time before starting a search cycle for a better modulation.
This has been shown to give better results.
Also change the name of the timeout define to better match its
description.
Signed-off-by: NEyal Shapira <eyal@wizery.com>
Signed-off-by: NEmmanuel Grumbach <emmanuel.grumbach@intel.com>

Rename for clearer names.
Signed-off-by: NEyal Shapira <eyal@wizery.com>
Signed-off-by: NEmmanuel Grumbach <emmanuel.grumbach@intel.com>