ath9k_hw: tweak noise immunity thresholds for older chipsets

Older chipsets are more sensitive to high PHY error counts, and the
current noise immunity thresholds were based on tests run at QCA with
newer chipsets.

This patch brings back the values from the old ANI implementation for
old chipsets, and it also disables weak signal detection on an earlier
noise immunity level, to improve overall radio stability on affected
devices.

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

ath9k: Remove unused ANI commands

Signed-off-by: Sujith Manoharan <c_manoha@qca.qualcomm.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

ath9k: Fix ANI for AP mode

The commit "ath9k: Fix ANI monitoring" reverted an earlier
commit that adjusted ANI to improve performance. But, this causes
adverse effects in AP mode (as reported by Felix based on an OpenWrt
report). Use the older INI/period configuration for now until more
testing is done.

Cc: Felix Fietkau <nbd@openwrt.org>
Cc: Rajkumar Manoharan <rmanohar@qca.qualcomm.com>
Signed-off-by: Sujith Manoharan <c_manoha@qca.qualcomm.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

ath9k: Fix ANI trigger threshold

Since raising/lowering the limits based on INI has
been changed, the error limit for OFDM has to be 1000,
not 3500.

Signed-off-by: Sujith Manoharan <c_manoha@qca.qualcomm.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

ath9k: Remove unused ANI macros

Signed-off-by: Sujith Manoharan <c_manoha@qca.qualcomm.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

ath9k: Fix ANI monitoring

The commit "ath9k_hw: improve ANI processing and rx desensitizing parameters"
changed various ANI operational parameters to address a specific
card/environment. This is not really applicable for other cards
in general usage.

As per internal documentation, lowering the immunity level can be
done only after 5 periods have passed and the CCK/OFDM errors are
below the low watermak threshold - which have been fixed at 300 and
400 respectively by the sytems team.

Raising the immunity level can be done when CCK/OFDM errors exceed
600 and 1000 (per second).

Set these values once during attach.

Signed-off-by: Sujith Manoharan <c_manoha@qca.qualcomm.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

ath9k: Print ANI statistics in debugfs

Signed-off-by: Sujith Manoharan <c_manoha@qca.qualcomm.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

ath9k: Set ofdmWeakSigDetect directly

The macros ATH9K_ANI_USE_OFDM_WEAK_SIG can be removed.

Signed-off-by: Sujith Manoharan <c_manoha@qca.qualcomm.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

ath9k: Simplify ANI initialization

The check "enable_ani" is not required since it is always
set to true and the logic for disabling/enabling ANI via
debugfs is done at a higher layer.

Signed-off-by: Sujith Manoharan <c_manoha@qca.qualcomm.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

ath9k_hw: reduce struct ar5416AniState size

It is kept per-channel, so removing unnecessary (or constant) fields from
it can save quite a bit of memory.

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

ath9k_hw: remove ath9k_hw_ani_setup and its variables

They are no longer needed for ANI functionality

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

ath9k: fix ANI operation in AP mode

ath9k_ani_reset (which is called at reset time) uses a state variable
ani->update_ani to prevent the ANI noise immunity state on the operating
channel from being overwritten by background scans. Unfortunately this
is also being set for AP mode, since it's mixed with code that is only
supposed to change the default settings after a reset.

In AP mode this has the side effect of having ANI run, but being unable to
change its runtime noise immunity level, making it effectively useless.

Fix this by getting rid of ani->update_ani and passing a parameter to
ath9k_hw_set_ofdm_nil and ath9k_hw_set_cck_nil instead.

Signed-off-by: Felix Fietkau <nbd@openwrt.org>
Cc: Rajkumar Manoharan <rmanohar@qca.qualcomm.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

ath9k_hw: rename mrcCCKOff to fix smatch warning

Rename mrcCCKOff for better code readability and also fixes
the smatch warning.

drivers/net/wireless/ath/ath9k/ar9003_phy.c:982
ar9003_hw_ani_control() Error invalid range 1 to 0.

Signed-off-by: Rajkumar Manoharan <rmanohar@qca.qualcomm.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

ath9k_hw: clean up defines and variables from the ANI implementation split

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

ath9k_hw: remove confusing logic inversion in an ANI variable

Code using this had already triggered smatch complaints, so remove it before
it gets fixed the wrong way.

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

ath9k_hw: remove aniState->noiseFloor

I don't know why somebody decided to keep a cached copy of beacon rssi in a
variable called 'noiseFloor', but the caching is unnecessary and the variable
name is confusing, so let's just get rid of it entirely.

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

ath9k_hw: improve ANI processing and rx desensitizing parameters

This patch improves ANI operations by switching among the immunity
levels based on PHY errors and beacon rssi which will adjust receiver
desensitizing parameters. The changes are

* Configure the Weak Signal Detection based on current immunity value.
* At highest OFDM immunity level poor performance was observed with
strong interference. By tuning the FIR step and spur immunity levels
and not changing any weak signal detection thresholds at any level
helped to improve the performance.
* ANI took long time to recover back to lower immunity levels on heavy
data load. As the listen time got reset to zero before reaching to
the 5x of aniperiod, the immunity level is not lowering back even
without any interference. This patch fix that.

Cc: Paul Stewart <pstew@google.com>
Cc: Susinder Gulasekaran <susinder@qca.qualcomm.com>
Signed-off-by: Suresh Chandrasekaran <csuresh@qca.qualcomm.com>
Signed-off-by: Rajkumar Manoharan <rmanohar@qca.qualcomm.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

ath9k: Store noise immunity values across scanning

CCK/OFDM noise immunilty values are always reset to defaults
during bgscan. This could affect the link quality and
performance when the STA is associated in a noisy channel.
So do not override the learned values across the scanning.

Signed-off-by: Rajkumar Manoharan <rmanohar@qca.qualcomm.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

ath9k: minor cleanup in ani

removed a function declaration, removed a variable, renamed a variable

Signed-off-by: Mohammed Shafi Shajakhan <mohammed@qca.qualcomm.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

ath9k: Drag the driver to the year 2011

The Times They Are a-Changin'.

Signed-off-by: Sujith Manoharan <Sujith.Manoharan@atheros.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

ath9k_hw: move the cycle counter tracking to ath

Instead of keeping track of wraparound, clear the counters on every
access and keep separate deltas for ANI and later survey use.
Also moves the function for calculating the 'listen time' for ANI

Signed-off-by: Felix Fietkau <nbd@openwrt.org>
Signed-off-by: Bruno Randolf <br1@einfach.org>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

ath9k_hw: clean up ANI state handling

ANI state is kept per channel, so instead of keeping an array of ANI states
with an arbitrary size of 255, move the ANI state into the channel struct.

Move some config settings that are not per-channel out of
the per-channel struct to save some memory.

With those changes, ath9k_ani_restart_old and ath9k_ani_restart_new can
be merged into a single function.

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

ath9k_hw: merge codepaths that access the cycle counter registers

The cycle counters are used by ANI to determine the amount of time that the
radio spent not receiving or transmitting. They're also used for debugging
purposes if the baseband watchdog on AR9003 detects a lockup.
In the future, we want to use these counters to determine the medium utilization
and export this information via survey. For that, we need to make sure that
the counter is only accessed from one place, which also ensures that
wraparounds won't occur at inconvenient points in time.

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

ath9k: add new ANI implementation for AR9003

This adds support for ANI for AR9003. The implementation for
ANI for AR9003 is slightly different than the one used for
the older chipset families. It can technically be used for
the older families as well but this is not yet fully tested
so we only enable the new ANI for the AR5008, AR9001 and AR9002
families with a module parameter, force_new_ani.

The old ANI implementation is left intact.

Details of the new ANI implemention:

* ANI adjustment logic is now table driven so that each ANI level
setting is parameterized. This makes adjustments much more
deterministic than the old procedure based logic and allows
adjustments to be made incrementally to several parameters per
level.

* ANI register settings are now relative to INI values; so ANI
param zero level == INI value. Appropriate floor and ceiling
values are obeyed when adjustments are combined with INI values.

* ANI processing is done once per second rather that every 100ms.
The poll interval is now a set upon hardware initialization and
can be picked up by the core driver.

* OFDM error and CCK error processing are made in a round robin
fashion rather than allowing all OFDM adjustments to be made
before CCK adjustments.

* ANI adjusts MRC CCK off in the presence of high CCK errors

* When adjusting spur immunity (SI) and OFDM weak signal detection,
ANI now sets register values for the extension channel too

* When adjusting FIR step (ST), ANI now sets register for FIR step
low too

* FIR step adjustments now allow for an extra level of immunity for
extremely noisy environments

* The old Noise immunity setting (NI), which changes coarse low, size
desired, etc have been removed. Changing these settings could affect
up RIFS RX as well.

* CCK weak signal adjustment is no longer used

* ANI no longer enables phy error interrupts; in all cases phy hw
counting registers are used instead

* The phy error count (overflow) interrupts are also no longer used
for ANI adjustments. All ANI adjustments are made via the polling
routine and no adjustments are possible in the ISR context anymore

* A history settings buffer is now correctly used for each channel;
channel settings are initialized with the defaults but later
changes are restored when returning back to that channel

* When scanning, ANI is disabled settings are returned to (INI) defaults.

* OFDM phy error thresholds are now 400 & 1000 (errors/second units) for
low/high water marks, providing increased stability/hysteresis when
changing levels.

* Similarly CCK phy error thresholds are now 300 & 600 (errors/second)

Signed-off-by: Luis R. Rodriguez <lrodriguez@atheros.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

ath9k_hw: allow for spliting up ANI operations by family

The AR9003 hardware family will use a slightly modified ANI
implementation which has not yet been tested on the other hardware
families. To allow for this new ANI implementation a few ANI
calls need to be abstracted away. This patch just allows for
each hardware family to declare their own ANI ops and annotates
the current ANI implementation as old.

Signed-off-by: Luis R. Rodriguez <lrodriguez@atheros.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

ath9k_hw: Remove pointless ANI deinit

There is no reason to disable the PHY Error / MIB counters
when the module is being unloaded.

Signed-off-by: Sujith <Sujith.Manoharan@atheros.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

ath9k: Nuke struct ath9k_node_stats

Other than ns_avgbrssi (Average beacon rssi) no data of
ath9k_node_stats is being used anywhere. Nuke this structure
and move its only useful member to ar5416Anistate. Also cleanup
this redundant data in ath_softc.

Signed-off-by: Vasanthakumar Thiagarajan <vasanth@atheros.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

ath9k: Fix bug in retrieving average beacon rssi

Currently the beacon rssi that LPF gives is divided and rounded
up by ATH_RSSI_EP_MULTIPLIER twice. This will leave the incorrect rssi
in ANI. Having correct rssi in ANI fixes the connection stability at
< 30dB rssi range. This patch removes the unncessary computation of average
rssi over already valid average rssi. Also removes the redundant macros to
find average rssi.

Signed-off-by: Vasanthakumar Thiagarajan <vasanth@atheros.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

ath9k: Remove has_hw_phycounters

PHY counters are available in all chipsets supported
by ath9k. Remove the check.

Signed-off-by: Sujith <Sujith.Manoharan@atheros.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

ath9k: rename ath9k_hw_ani_detach() to ath9k_hw_ani_disable()

Signed-off-by: Luis R. Rodriguez <lrodriguez@atheros.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

ath9k: describe hw initialization better

During initialization ath9k tends to use "attach" to when we
initialize hardware due to the fact we used to attach a "HAL".
The notion of a HAL is long gone, so lets just be clear on what
we are doing.

Signed-off-by: Luis R. Rodriguez <lrodriguez@atheros.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

atheros: put atheros wireless drivers into ath/

Signed-off-by: Luis R. Rodriguez <lrodriguez@atheros.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>