ath9k: restart hardware after noise floor calibration failure

When NF calibration fails, the radio often becomes deaf. The usual
hardware hang checks do not detect this, so it's better to issue a reset
when that happens.

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

ath9k: add noise floor parameter to ath9k_hw_getchan_noise

Add nf parameter to ath9k_hw_getchan_noise() in order to compute NF for EXT
chains with the same scale of noise floor calculated on CTL chains.
ath9k_hw_getchan_noise() will be used in ath_process_fft() for spectral scan on
HT40 channels

Signed-off-by: Lorenzo Bianconi <lorenzo.bianconi83@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

ath9k_hw: make various ar5416/ar91xx rf banks const

Banks 0-3,7 are neither modified at run time, nor SREV dependent.

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

ath9k_hw: Fix signal strength / channel noise reporting

While AR_PHY_CCA_NOM_VAL_* does contain the expected internal noise floor
for a chip measured in clean air, it refers to the lowest expected reading.

Depending on the frequency, this measurement can vary by about 6db, thus
causing a higher reported channel noise and signal strength.

Factor in the 6db offset when converting internal noisefloor to channel noise.

This patch makes the reported values more accurate for all chips without
affecting NF calibration behavior.

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

ath9k_hw: remove redundant arguments to INIT_INI_ARRAY

The row/column sizes can be derived from the array argument within the macro
itself, which is less error prone. In a few cases the supplied column size
was actually wrong.

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

ath9k_hw: fix a comment

also remove an unused macro and a function declaration

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

ath9k_hw: calculate a much better approximation of channel noise

Currently ath9k presents the internal calibrated noise floor as channel
noise measurement, however this results in highly chip specific values
that are only useful as relative measurements but do not resemble any
real channel noise values.

In order to give a much better approximation of the real channel noise,
add the difference between the measured noise floor and the nominal
chip specific noise floor to the default minimum channel noise value,
which is currently used to calculate the signal strength from the RSSI
value. This may not be 100% accurate, but it's much better than what's
there before.

Signed-off-by: Felix Fietkau <nbd@openwrt.org>
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: remove get_channel_noise function

currently ath9k_hw_getchan_noise is not used anywhere

Signed-off-by: Mohammed Shafi Shajakhan <mshajakhan@atheros.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

ath9k_hw: clean up calibration flags

The calibration actual calibration flags are only used by the per chip family
source files, so it makes more sense to define them in those files instead
of globally. That way the code has to test for less flags.

Also instead of using a separate callback for testing whether a particular
calibration type is supported, simply adjust ah->supp_cals in the calibration
init which is called right after the hardware reset, before any of the
calibrations are run.

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

ath9k_hw: remove some useless calibration data

The percal struct and bitmask for the initial DC calibration are not
used anywhere, so they can be removed.

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

ath9k: use AP beacon miss as a trigger for fast recalibration

When beacons get stuck in AP mode, the most likely cause is interference.
Such interference can often go on for a while, and too many consecutive
beacon misses can lead to connected clients getting dropped.

Since connected clients might not be subjected to the same interference
if that happens to be very local, the AP should try to deal with it as
good as it can. One way to do this is to trigger an NF calibration with
automatic baseband update right after the beacon miss. In my tests with
very strong interference, this allowed the AP to continue transmitting
beacons after only 2-3 misses, which allows a normal client to stay
connected.

With some of the newer - really sensitive - chips, the maximum noise
floor limit is very low, which can be problematic during very strong
interference. To avoid an endless loop of stuck beacons -> nfcal ->
periodic calibration -> stuck beacons, the beacon miss event also sets
a flag, which allows the calibration code to bypass the chip specific
maximum NF value. This flag is automatically cleared, as soon as the
first NF median goes back below the limits for all chains.

In my tests, this allowed an ath9k AP to survive very strong interference
(measured NF: -68, or sometimes even higher) without losing connectivity
to its clients. Even under these conditions, I was able to transmit
several mbits/s through the interface.

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

ath9k_hw: fix a noise floor calibration related race condition

On AR5008-AR9002, other forms of calibration must not be started while
the noise floor calibration is running, as this can create invalid
readings which were sometimes not even recoverable by any further
calibration attempts.

This patch also ensures that the result of noise floor measurements
are processed faster and also allows the result of the initial
calibration on reset to make it into the NF history buffer

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

ath9k_hw: clean up per-channel calibration data

The noise floor history buffer is currently not kept per channel, which
can lead to problems when changing channels from a clean channel to a
noisy one. Also when switching from HT20 to HT40, the noise floor
history buffer is full of measurements, but none of them contain data
for the extension channel, which it needs quite a bit of time to recover
from.

This patch puts all the per-channel calibration data into a single data
structure, and gives the the driver control over whether that is used
per-channel or even not used for some channels.

For ath9k_htc, I decided to keep this per-channel in order to avoid
creating regressions.

For ath9k, the data is kept only for the operating channel, which saves
some space. ath9k_hw takes care of wiping old data when the operating
channel or its channel flags change.

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

ath9k_hw: clean up and fix initial noise floor calibration

On AR9003 the initial noise floor calibration is currently triggered
at the end of the reset without allowing the hardware to update the
baseband settings. This could potentially make scans in noisy
environments a bit more unreliable, so use the same calibration
sequence that is used on AR9002.

Signed-off-by: Felix Fietkau <nbd@openwrt.org>
Acked-by: Luis R. Rodriguez <lrodriguez@atheros.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

ath9k: merge noisefloor load implementations

AR5008+ and AR9003 currently use two separate implementations of the
ath9k_hw_loadnf function. There are three main differences:

- PHY registers for AR9003 are different
- AR9003 always uses 3 chains, earlier versions are more selective
- The AR9003 variant contains a fix for NF load timeouts

This patch merges the two implementations into one, storing the
register array in the ath_hw struct. The fix for NF load timeouts is
not just relevant for AR9003, but also important for earlier hardware,
so it's better to just keep one common implementation.

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

ath9k_hw: sanitize noise floor values properly on all chips

This refactors the noise floor range checks to make them generic,
and adds proper ranges for each supported chip type.

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

ath9k_hw: fill in the callbacks for calibration for AR9003

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

ath9k_hw: abstract loading noisefloor

This is the last call on calib.c which acceses PHY stuff,
with this change we calib.c is now generic between both
all supported hardware families.

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

ath9k_hw: split calib code by hardware families

Calibration code touches phy registers and since these
change the calibration code needs to be abstracted.

Noise floor calibration is the only thing remaining but
since the remaining calls only touch the AR_PHY_AGC_CONTROL
register we'll just define that register conditionally, that
will be done separately. The goal is to remove the dependency
of ar9002_phy.h on calib.c

This also adds stubs to be filled for AR9003 calibration code.

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

atheros: add common debug printing

ath9k uses this for now, ath9k_htc is expected to re-use this
as well. We lave ath5k as is, but it certainly can also be
converted later.

The ath9k module parameter and debugfs entry is kept.

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

ath9k: Set default noise floor value for AR9287

The default noise floor was never initialized for
AR9287.This patch helps in reporting the correct
RSSI for this version of chipset.

Signed-off-by: Vivek Natarajan <vnatarajan@atheros.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

ath9k: Reduce the frequency of PA offset calibration

PA calibration need not be done if the offset is not varying.
The current logic does PA calibration even if the offset is the
same.

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

ath9k: Manipulate and report the correct RSSI

RSSI reported by the RX descriptor requires little manipulation.
Manipulate and report the correct RSSI to the stack. This will
fix the improper signal levels reported by iwconfig iw dev wlanX
station dump. Also the Link Quality reported seems to be varying
(falls to zero also sometimes) when iperf is run from STA to AP.

Also use the default noise floor for now as the one reported
during the caliberation seems to be wrong.

The Signal and Link Quality before this patch (taken while TX is
in progress from STA to AP)

09:59:13.285428037 Link Quality=29/70 Signal level=-81 dBm
09:59:13.410660084 Link Quality=20/70 Signal level=-90 dBm
09:59:13.586864392 Link Quality=21/70 Signal level=-89 dBm
09:59:13.710296281 Link Quality=21/70 Signal level=-89 dBm
09:59:13.821683064 Link Quality=25/70 Signal level=-85 dBm
09:59:13.933402989 Link Quality=24/70 Signal level=-86 dBm
09:59:14.045839276 Link Quality=26/70 Signal level=-84 dBm
09:59:14.193926673 Link Quality=23/70 Signal level=-87 dBm
09:59:14.306230262 Link Quality=31/70 Signal level=-79 dBm
09:59:14.419459667 Link Quality=26/70 Signal level=-84 dBm
09:59:14.530711167 Link Quality=37/70 Signal level=-73 dBm
09:59:14.642593962 Link Quality=29/70 Signal level=-81 dBm
09:59:14.754361169 Link Quality=21/70 Signal level=-89 dBm
09:59:14.866217355 Link Quality=21/70 Signal level=-89 dBm
09:59:14.976963623 Link Quality=28/70 Signal level=-82 dBm
09:59:15.089149809 Link Quality=26/70 Signal level=-84 dBm
09:59:15.205039887 Link Quality=27/70 Signal level=-83 dBm
09:59:15.316368003 Link Quality=23/70 Signal level=-87 dBm
09:59:15.427684036 Link Quality=36/70 Signal level=-74 dBm
09:59:15.539756380 Link Quality=21/70 Signal level=-89 dBm
09:59:15.650549093 Link Quality=22/70 Signal level=-88 dBm
09:59:15.761171672 Link Quality=32/70 Signal level=-78 dBm
09:59:15.872793750 Link Quality=23/70 Signal level=-87 dBm
09:59:15.984421694 Link Quality=22/70 Signal level=-88 dBm
09:59:16.097315093 Link Quality=21/70 Signal level=-89 dBm

The link quality and signal level after this patch (take while
TX is in progress from STA to AP)

17:21:25.627848091 Link Quality=65/70 Signal level=-45 dBm
17:21:25.762805607 Link Quality=65/70 Signal level=-45 dBm
17:21:25.875521888 Link Quality=66/70 Signal level=-44 dBm
17:21:25.987468448 Link Quality=66/70 Signal level=-44 dBm
17:21:26.100628151 Link Quality=66/70 Signal level=-44 dBm
17:21:26.213129671 Link Quality=66/70 Signal level=-44 dBm
17:21:26.324923070 Link Quality=65/70 Signal level=-45 dBm
17:21:26.436831357 Link Quality=65/70 Signal level=-45 dBm
17:21:26.610356973 Link Quality=65/70 Signal level=-45 dBm
17:21:26.723340047 Link Quality=65/70 Signal level=-45 dBm
17:21:26.835715293 Link Quality=64/70 Signal level=-46 dBm
17:21:26.949542748 Link Quality=64/70 Signal level=-46 dBm
17:21:27.062261613 Link Quality=65/70 Signal level=-45 dBm
17:21:27.174511563 Link Quality=64/70 Signal level=-46 dBm
17:21:27.287616232 Link Quality=64/70 Signal level=-46 dBm
17:21:27.400598119 Link Quality=64/70 Signal level=-46 dBm
17:21:27.511381404 Link Quality=64/70 Signal level=-46 dBm
17:21:27.624530421 Link Quality=65/70 Signal level=-45 dBm
17:21:27.737807109 Link Quality=64/70 Signal level=-46 dBm
17:21:27.850861352 Link Quality=65/70 Signal level=-45 dBm
17:21:27.963369436 Link Quality=64/70 Signal level=-46 dBm
17:21:28.076582289 Link Quality=64/70 Signal level=-46 dBm

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

ath9k: Use a consistent naming convention

This patch replaces old 'hal_' prefixes with 'ath9k_'.

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

ath9k: Cleanup calibration interface

This patch cleans up the functions dealing with calibration,
using proper return values.
ath9k_hw_per_calibration(), ath9k_hw_calibrate now return bool values
instead of setting error values in the function arguments.

Signed-off-by: Sujith <Sujith.Manoharan@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>