for the AR9280 based NICs if it's actually enabled.
Some of the OLC code was erroneously called during setup
and calibration. This may have caused some incorrect behaviour.
table which contains the per-rate target TX power.
This code is shared between the v14 eeprom board setup (AR5416, AR9160,
AR9280) and will also be used by the upcoming Kite (AR9287) support.
* grab the main, alt and selected LNA config
* add some optional / disabled logging code
* add a check to reject packets with an invalid main rssi too,
in case the alt is the active receive chain and main is -ve.
Note: The software-controlled combined diversity code is still disabled.
environments.
In setups where NF calibration can take a while, don't load the CCA
and kick off a new NF calibration if the previous one hasn't yet
completed. This shouldn't happen unless the environment is noisy but
those exist (hi phk!).
Here, if the previous NF hasn't completed when ar5416LoadNf() is run
(which reads the NF), it skips updating the history buffer, loading
the NF CCA array and kicking off the next NF cal. It's hoped it'll
occur in the next long calibration interval.
Obtained from: Atheros, ath9k, my local HAL
This is taking quite a while for some people in some situations
(eg AR5418 in phk's Abusive Radio Environment).
Instead, the rest of the calibration related code should
ensure that a NF calibration has occured before reading NF
values and kicking off another NF calibration.
The channel should also likely be marked as "noisy" (CWINT)
if the NF calibration takes too long.
* Correct some of the silicon revision checks to match what
the Atheros HAL does. (See [1] below.)
* Move the PA cal and init cal method assignment to -after-
the mac version/revision IDs are stored. The AR9285 init
cal was never being called.
* Enable ANI.
Note Kite 1.0 and 1.1 were prototypes that shouldn't be seen
in the wild. Linux ath9k simply removed the prototype code from
their codebase. I'm going to leave it in there for now but
make it conditionally compilable in the future.
Obtained from: Atheros
from Atheros as to what/when this is supposed to be enabled.
Using the default RX fast diversity settings seems to help quite
a bit.
Whilst I'm here, change the prototype to return HAL_BOOL rather than int.
For now, the diversity settings are controlled by 'txantenna',
-not- rxantenna. This is because the earlier chipsets had
controllable TX diversity; the RX antenna setting twiddles
the default antenna register. I'll try sort that stuff out at
some point.
Call the antenna switch function from the board setup function
so scans, channel changes, mode changes, etc don't set the
diversity back to a default state too far from what's intended.
Things to todo:
* Squirrel away the last antenna diversity/combining parameters
and restore them during board setup if HAL_ANT_VARIABLE is
defined. That way scans, etc don't reset the diversity settings.
* Add some more public facing statistics, rather than what's
simply logged under HAL_DEBUG_DIVERSITY.
For now, the fixed antenna settings behave better than variable
settings for me. I have some further fiddling to do..
Obtained from: Atheros
The macro which I incorrectly copied into ah_internal.h assumed
that it'd be called with an AR_SREV_MERLIN_20() check to ensure
it was only enabled for Merlin (AR9280) silicon revision 2.0 or
later.
Trouble is, the 5GHz fast clock EEPROM flag is only valid for
EEPROM revision 16 or greater; it's assumed to be enabled
by default for Merlin rev >= 2.0. This meant it'd be incorrectly
set for AR5416 and AR9160 in 5GHz mode.
This would have affected non-default clock timings such as SIFS,
ACK and slot time. The incorrect slot time was very likely wrong
for 5ghz mode.
* Modify AR_SREV_MERLIN_20() to match the Atheros/Linux ath9k behaviour -
its supposed to match Merlin 2.0 and later Merlin chips.
AR_SREV_MERLIN_20_OR_LATER() matches AR9280 2.0 and later chips
(AR9285, AR9287, etc.)
for the given channel is available.
It isn't used yet; ar5416GetWirelessModes() needs to be taught
about this rather than assuming HT20/HT40 is available.
This seems to make the AR9160 behave better during heavy scanning,
where before it'd hang and require a hard reset to recover.
Obtained From: Linux ath9k, Atheros
modifying AR_DIAG_SW.
There's a hardware workaround which sets disabling some errors
early at startup and clears said bits before the PCU begins
receiving - it does this to avoid RX descriptor status errors.
It's possible these bits aren't being completely properly twiddled
in all instances; but in particular if the diag_reg HAL variable
is set it won't be setting these bits correctly. I'll review this
at some point.
* Disable multicast search on mac address and key id - the driver
doesn't use it at the moment and thus adhoc may be broken for
merlin and later.
* Change this to be for Merlin 1.0 (which from what I understand
wasn't ever publicly released) to be more correct.
Apparently all three RX chains need to be enabled before initial calibration
is done, even if only two are configured.
Reorder the alt chain swap bit to match what the Atheros HAL is doing.
Obtained From: ath9k, Atheros
* Shuffle some of the capability numbers around to match the
Atheros HAL capability IDs, just for consistency.
* Add some new capabilities to FreeBSD from the Atheros
HAL which will be be shortly used when new chipsets are added
(HAL SGI-20 support is for Kiwi/AR9287 support); for
TX aggregation (MBSSID aggregate support, WDS aggregation
support); CST/GTT support for carrier sense/TX timeout.
channel when the channel is HT/40.
The new ANI code (primarily for the AR9300/AR9400) in ath9k sets this
register but the ANI code for the previous 11n chips didn't set this.
Unlike ath9k, only set this for HT/40 channels.
Obtained From: ath9k
These describe FCC/Japan channel and DFS behaviour.
The AR9285 and later chips don't set these bits in the eeprom, the correct
behaviour is to just assume all five bits are enabled.
specific.
The Atheros HAL and FreeBSD HAL share the same capabilities up
until HAL_CAP_11D, where things begin to diverge.
I'll look at tidying these up soon.
Obtained from: Atheros
* Add Howl (ar9130) to the list of chips that have DFS/BB/MAC hangs
* Don't treat unknown BB hangs as fatal; ath9k/Atheros HAL don't
treat it as such.
* Add HAL_DEBUG_DFS to the debug fields in ath_hal/ah_debug.h
The BB hang check simply loops over an observation register checking
for a stuck state engine, but it can happen under high traffic
conditions. Ath9k and the Atheros HAL simply log a debug message and
continue.
Private to FreeBSD:
* Add HAL_DEBUG_HANG to the debug fields
* Change the hang debugging to HAL_DEBUG_HANG rather than HAL_DEBUG_DFS
like in the Atheros HAL.
Obtained from: Atheros
For now, these are equivalent macros. AR_SREV_OWL{X}_OR_LATER
will later change to exclude Howl (AR9130) in line with what
the Atheros HAL does.
This should not functionally change anything.
Obtained from: Atheros
A quick story, which is partially documented in the commit.
The silicon revision in Linux ath9k and the Atheros HAL use an
AR_SREV_REVISION mask of 0x07.
FreeBSD's HAL uses the AR5212 AR_SREV_REVISION mask of 0x0F.
Thus the OWL silicon revisions were coming through as 0xA, 0xB,
0xC, rather than 0x0, 0x1 and 0x2.
My ath9k-sourced AR_SREV_OWL_<X> macros were thus using the wrong
silicon revision values and wouldn't correctly match.
This commit does a few things:
* Change the AR_SREV_OWL_<x> macros to use the AR_SREV_REVISION_OWL_*
values, not AR_XSREV_REVISION_OWL macros;
* Disable AR_XSREV_REVISION_OWL_* values;
* Modify the IS_5416 to properly check the MAC is OWL, rather than
potentially matching on non-OWL revisions (which shouldn't happen
unless there's a silicon revision of higher than 0x9 in a later
chip..)
* Add a couple more macros from the Atheros HAL for compatibility.
The main difference now is that the Atheros HAL defines
AR_SREV_OWL_{20,22}_OR_LATER subtly differently - it fails on all HOWL
silicon. The AR_SREV_5416_*_OR_LATER macros match on the relevant OWL
version -and- all HOWL versions, along with subsequent versions.
A subsequent commit is going to migrate the uses of AR_SREV_OWL_X_OR_LATER
to AR_SREV_5416_X_OR_LATER to match what's going on in the Atheros HAL.
There's only two uses of AR_SREV_OWL_X_OR_LATER which currently don't
apply to FreeBSD but it may do in the future.
Yes, it's all confusing!
Quoting the ath9k commit message:
At present the noise floor calibration is processed in supported
control and extension chains rather than required chains.
Unnccesarily doing nfcal in all supported chains leads to
invalid nf readings on extn chains and these invalid values
got updated into history buffer. While loading those values
from history buffer is moving the chip to deaf state.
This issue was observed in AR9002/AR9003 chips while doing
associate/dissociate in HT40 mode and interface up/down
in iterative manner. After some iterations, the chip was moved
to deaf state. Somehow the pci devices are recovered by poll work
after chip reset. Raading the nf values in all supported extension chains
when the hw is not yet configured in HT40 mode results invalid values.
Reference: https://patchwork.kernel.org/patch/753862/
Obtained from: Linux ath9k
The checks should function as follows:
* AR_SREV_<silicon> : check macVersion matches that version id
* AR_SREV_<silicon>_<revision> : check macVersion and macRevision match
the version / revision respectively
* AR_SREV_<silicon>_<revision>_OR_LATER: check that
+ if the chip silicon version == macVersion, enforce revision >= macRevision
+ if the chip silicon version > macVersion, allow it.
For example, AR_SREV_MERLIN() only matches AR9280 (any revision),
AR_SREV_MERLIN_10() would only match AR9280 version 1.0, but
AR_SREV_MERLIN_20_OR_LATER() matches AR9280 version >= 2.0 _AND_
any subsequent MAC (So AR9285, AR9287, etc.)
The specific fixes which may impact users:
* if there is Merlin hardware > revision 2.0, it'll now be correctly
matched by AR_SREV_MERLIN_20_OR_LATER() - the older code simply
would match on either Merlin 2.0 or a subsequent MAC (AR9285, AR9287, etc.)
* Kite version 1.1/1.2 should now correctly match. As these macros
are used in the AR9285 reset/attach path, and it's assumed that the
hardware is kite anyway, the behaviour shouldn't change. It'll only
change if these macros are used in other codepaths shared with
older silicon.
Obtained from: Linux ath9k, Atheros
The AR9130 is an AR9160/AR5416 family WMAC which is glued directly
to the AR913x SoC peripheral bus (APB) rather than via a PCI/PCIe
bridge.
The specifics:
* A new build option is required to use the AR9130 - AH_SUPPORT_AR9130.
This is needed due to the different location the RTC registers live
with this chip; hopefully this will be undone in the future.
This does currently mean that enabling this option will break non-AR9130
builds, so don't enable it unless you're specifically building an image
for the AR913x SoC.
* Add the new probe, attach, EEPROM and PLL methods specific to Howl.
* Add a work-around to ah_eeprom_v14.c which disables some of the checks
for endian-ness and magic in the EEPROM image if an eepromdata block
is provided. This'll be fixed at a later stage by porting the ath9k
probe code and making sure it doesn't break in other setups (which
my previous attempt at this did.)
* Sprinkle Howl modifications throughput the interrupt path - it doesn't
implement the SYNC interrupt registers, so ignore those.
* Sprinkle Howl chip powerup/down throughout the reset path; the RTC methods
were
* Sprinkle some other Howl workarounds in the reset path.
* Hard-code an alternative setup for the AR_CFG register for Howl, that
sets up things suitable for Big-Endian MIPS (which is the only platform
this chip is glued to.)
This has been tested on the AR913x based TP-Link WR-1043nd mode, in
legacy, HT/20 and HT/40 modes.
Caveats:
* 2ghz has only been tested. I've not seen any 5ghz radios glued to this
chipset so I can't test it.
* AR5416_INTERRUPT_MITIGATION is not supported on the AR9130. At least,
it isn't implemented in ath9k. Please don't enable this.
* This hasn't been tested in MBSS mode or in RX/TX block-aggregation mode.
Writing the TX power registers is the same between all of these chips
and later NICs (AR9287, AR9271 USB, etc.) so this will reduce code
duplication when those NICs are added to the HAL.
spurious (and fatal) interrupt errors.
One user reported seeing this:
Apr 22 18:04:24 ceres kernel: ar5416GetPendingInterrupts: fatal error,
ISR_RAC 0x0 SYNC_CAUSE 0x2000
SYNC_CAUSE of 0x2000 is AR_INTR_SYNC_LOCAL_TIMEOUT which is a bus timeout;
this shouldn't cause HAL_INT_FATAL to be set.
After checking out ath9k, ath9k_ar9002_hw_get_isr() clears (*masked)
before continuing, regardless of whether any bits in the ISR registers
are set. So if AR_INTR_SYNC_CAUSE is set to something that isn't
treated as fatal, and AR_ISR isn't read or is read and is 0, then
(*masked) wouldn't be cleared. Thus any of the existing bits set
that were passed in would be preserved in the output.
The caller in if_ath - ath_intr() - wasn't setting the masked value
to 0 before calling ath_hal_getisr(), so anything that was present
in that uninitialised variable would be preserved in the case above
of AR_ISR=0, AR_INTR_SYNC_CAUSE != 0; and if the HAL_INT_FATAL bit
was set, a fatal condition would be interpreted and the chip was
reset.
This patch does the following:
* ath_intr() - set masked to 0 before calling ath_hal_getisr();
* ar5416GetPendingInterrupts() - clear (*masked) before processing
continues; so if the interrupt source is AR_INTR_SYNC_CAUSE
and it isn't fatal, the hardware isn't reset via returning
HAL_INT_FATAL.
This doesn't fix any underlying errors which trigger
AR_INTR_SYNC_LOCAL_TIMEOUT - which is a bus timeout of some
sort - so that likely should be further investigated.
It's also marked inactive by the initvals, and enabled after
the baseband/PLL has been configured, but before the RF
registers have been programmed.
The origin and reason for this particular change is currently unknown.
Obtained from: Linux ath9k
Antenna diversity on the >= AR5416 is implemented differently than the
AR5212 and previous chips. So for now, and not to confuse things, just
disable it for now.
diversity.
This is bit dirty and likely should be revised at a later date,
with an eye to unifying/tidying up the whole diversity setup
and allowing developers to do "tricky stuff" as they desire.
For now, this works.
* add a new method, specifically for doing per-RX packet
antenna diversity
* set that HAL method only if it's Kite and a Kite chip that
does diversity.
* add a diversity flag to the HAL debugging section
* add a check to make sure the kite diversity code doesn't run
on boards that don't require it, as not all Kite chips will
implement it.
* add some debug statements when the diversity code makes
changes to the antenna diversity/combining setup.
Note: this HAL currently only supports the AR9285.
From Linux ath9k:
The problem is that when the attenuation is increased,
the rate will start to drop from MCS7 -> MCS6, and finally
will see MCS1 -> CCK_11Mbps. When the rate is changed b/w
CCK and OFDM, it will use register desired_scale to calculate
how much tx gain need to change.
The output power with the same tx gain for CCK and OFDM modulated
signals are different. This difference is constant for AR9280
but not AR9285/AR9271. It has different PA architecture
a constant. So it should be calibrated against this PA
characteristic.
The driver has to read the calibrated values from EEPROM and set
the tx power registers accordingly.
ctl/ext noise floor values.
This routine doesn't check to see whether the radio is MIMO
capable - instead, it simply returns either the raw values,
the "nominal" values if the raw values aren't yet available
or are invalid, or '0' values if there's no valid channel/
no valid MIMO values.
Callers are expected to verify the radio is a MIMO radio
(which for now means it's an 11n chipset, there are non-11n
MIMO chipsets out there but I don't think we support them,
at least in MIMO mode) before exporting the MIMO values.
upper-level HAL.
Right now the per-chain noise floor values aren't used anywhere in
the upper-level HAL, so the driver currently has no real reference
to compare the per-chain RSSI values to.
This is needed before per-chain RSSI values (for ctl and ext radios)
are can be thrown upstairs to the net80211 code.
From the ath9k source:
==
11N: we can no longer afford to self link the last descriptor.
MAC acknowledges BA status as long as it copies frames to host
buffer (or rx fifo). This can incorrectly acknowledge packets
to a sender if last desc is self-linked.
==
Since this is useful for pre-AR5416 chips that communicate PHY errors
via error frames rather than by on-chip counters, leave the support
in there, but disable it for AR5416 and later.
Introduce the AHB glue for Atheros embedded systems. Right now it's
hard-coded for the AR9130 chip whose support isn't yet in this HAL;
it'll be added in a subsequent commit.
Kernel configuration files now need both 'ath' and 'ath_pci' devices; both
modules need to be loaded for the ath device to work.
in the RX path when doing 11n and block-ack'ed frames. Apparently, the MAC
will loop over that self-linked descriptor and treat it as "good enough"
for (incorrectly!) ACKing the frames in the block-ack.
Until I figure out how to work around this issue in the future, this counter
will tell me if packet RX processing ever gets to the point where it's
touching the self-linked descriptor. If there's ever enough packets to get
to that point, BA's will be invalid and likely very unhappy.
I'll clear how it's supposed to work with Bernhard and then look
at enabling this in the correct situations.
But this -does- enable HT RTS protection (using the appropriate legacy
rates) if this bit of code is enabled.
by default.
Adventourous souls with an AR9220/AR9280 or later and who have a device
that sends PS-POLL frames may wish to try tinkering with this option and
get back to me.
Linux ath9k only enables this for AR9280 and later NICs; so
create a capability for it so it isn't enabled for earlier
NICs.
Enabling hardware PS-POLL support will come in a later commit
and will be disabled by default.
Even though they map to setting the error filter register,
ath9k also writes them untouched to AR_RX_FILTER.
The Force-BSSID match bit can stay high, as it maps to a
misc mode register setting rather than an RX filter bit.
The phyerr, radar and bssid-match bits aren't real bits, they map
to enabling bits in other registers. Move those out of the way of
valid RX filter bits.
Add a few new fields from ath9k - compba, ps-poll, mcast-bcast-all.
the channel width is ni->ni_chw, which is set to the negotiated channel
width. ni->ni_htflags is the capability, rather than the negotiated
value.
Teach both the TX path and the sample rate module about this.
This seems to work fine for STA but not HT/20 AP mode.
Further discussion with net80211 people will need to take place
to ensure that the right flags are set based on the negotiated
capabilities of the remote peer, rather than whatever the local
parameters are.
Sending short-gi frames in 20mhz may work on some chips but
it certainly isn't supported on anything currently supported
by the HAL; and sending HT40 frames in HT20 mode just plain
won't work.
settings, it seems that our defines are backwards and don't match what
is in the EEPROM documentation or internal driver.
The ath9k code used to have a bitfield here, rather than a uint8_t, and
there were #defines used to swap the order based on the endian of the
platform - this wasn't because of nybble or bit ordering of the
underlying host but because of what the compiler was doing.
This may be the reason for the backwards field numbers, as ath9k had
similar issues.
the AR9285 so I'll leave it off for that.
Ath9k sources indiciate that one of the ANI modes interferes with
RIFS detection, so match ath9k and disable that.
* The existing interrupt mitigation code didn't mitigate anything - the
per-packet TX/RX interrupts are still occuring. It's possible this
worked for the AR5416 but not any later chipsets; I'll investigate and
update as needed.
* Set both the RX and TX threshold registers whilst I'm at it.
This is verified to work on the AR9220 and AR9160. I'm leaving it off
by default in case it's truely broken, but I need to have it enabled
when doing 11n testing or interrupt loads exceed 10,000 interrupts/sec.
At least one AR5416 user has reported measurable throughput drops
with this option. For now, disable it and make it a run-time
twiddle. It won't take affect until the next radio programming
trip though (eg channel scan, channel change.)
so there's no need to enable the RX of invalid frames just to do ANI.
The if_ath code and AR5212 ANI code setup the RX filter bits to enable
receiving OFDM/CCK errors if the device doesn't have the hardware
MIB counters. It isn't initialising it for the AR5416+ because all of
those chips have hardware MIB counters.
This fixes the odd (and performance affecting!) situation where if ani
is enabled (via sysctl dev.ath.X.intmit) then suddenly there's be a very
large volume of phy errors - which is good to track, but not what was
intended. Since each PHY error is a received (0 length) frame, it can
significantly tie up the RX side of things.
It's still not ready for prime-time - there's some TX niggles with these 11n
cards that I'm still trying to wrap my head around, and AMPDU-TX is just not
implemented so things will come to a crashing halt if you're not careful.
This fix modifies the const addac initval array, rather than modifying
a local copy. It means that running >1 AR9160 on a board may prove to
be unpredictable.
The AR5416 init path also does something similar, so supporting
>1 AR5416 of different revisions could cause problems.
The later fix will be to create a private copy of the Addac data
for the AR5416, AR9160 (and AR9100 when it's merged in) and then
modify that as needed.
Obtained From: Linux ath9k
I found this when trying to figure out why the RX PHY error count
didn't match the OFDM error count ANI was using. It turns out
there was two problems:
* What this commit addresses - using the wrong mask for OFDM errors,
and
* The RX filter is set incorrectly after a channel scan (at least)
even if interference mitigation is enabled by default.
ANI is still disabled by default for the AR5416 and later chips.
bring it in line with the rest of the register initialisation.
I've verified that the 2/5ghz board values written to the
chip match what was previously written.
* add pspoll/uapsd queue setup defaults;
* enable the exponential backoff window rather than the random
backoff window when doing TX contention management.
would be a problem, make sure it isn't overwritten by whatever is in
there at cold reset.
This brings the > ar5416 init path treatment of AR_MISC_MODE.
* Pull out the static rix stuff into a different function
* I know this may slightly drop performance, but check if a static
rix is needed before each packet TX.
* Whilst I'm at it, add a little extra debugging to the rate
control stuff to make it easier to follow what's going on.
Give it a good go (32 attempts) and then print out a warning that's
going to occur whether HAL debugging is enabled or not. Then don't
abort the radio setup; just continue merrily along.
This should fix the issue that users were having where scanning would
occasionally fail on the active channel, causing traffic to cease
until the radio scanned again.
not needed.
These calibrations are only applicable if the chip operating mode
engages both interleaved RX ADCs (ie, it's compensating for the
differences in DC gain and DC offset -between- the two ADCs.)
Otherwise the chip reads values of 0x0 for the secondary ADC
(as I guess it's not enabled here) and thus writes potentially
bogus info into the chip.
I've tested this on the AR9160 and AR9280; both behave themselves
in 11g mode with these calibrations disabled.
for fixing them based on the ath9k related TXQ fixes.
I've done this so people can go over the history of the diffs to the original
AR5212 routines (which AR5416 and later chips use) to see what's changed.
This commit really is "fix the OFDM duration calculation to match reality when
running in 802.11g mode."
The AR5212 init vals set AR_MISC_MODE to 0x0 and all the bits that can be set are
set through code.
The AR5416 and later initvals set AR_MISC_MODE to various other values (with
the AR5212 AR_MISC_MODE options cleared), which include AR_PCU_CCK_SIFS_MODE .
This adds 6uS to SIFS on non-CCK frames when transmitting.
This fixes the issue where _DATA_ 802.11g OFDM frames were being TX'ed with
the ACK duration set to 38uS, not 44uS as on the AR5212 (and other devices.)
The AR5212 TX pathway obeys the software-programmed duration field in the packet,
but the 11n TX pathway overrides that with a hardware-calculated duration. This
was getting it wrong because of the above AR_MISC_MODE setting. I've verified
that 11g data OFDM frames are now being TXed with the correct ACK+SIFS duration
programmed in.
Since ath9k does some slightly different bit fiddling when setting up
the TX queues, it may that the TX queue setup/reset functions will need
overriding later on.
This does a few things in particular:
* Abstracts out the gain control settings into a separate function;
* Configure antenna diversity, LNA and antenna gain parameters;
* Configure ob/db entries - the later v4k EEPROM modal revisions have
multiple OB/DB parameters which are used for some form of
calibration. Although the radio does have defaults for each,
the EEPROM can override them.
This resolves the AR2427 related issues I've been seeing and makes
it stable at all 11g rates for both TX and RX.
The offsets didn't match the assumption that nfarray[] is ordered by the
chainmask bits and programmed via the register order in ar5416_cca_regs[].
This repairs that damage and ensures that chain 1 is programmed correctly.
(And extension channels will now be programmed correctly also.)
This fixes some of the stuck beacons I've been seeing on my AR9160/AR5416
setups - because Chain 1 would be programmed -80 or -85 dBm, which is
higher than the actual noise floor and thus convincing the radio that
indeed it can't ever transmit.
rather than duplicating them for the v14 (ar5416+) and v4k (ar9285) codebases.
Further chipsets (eg the AR9287) have yet another EEPROM format which will use
these routines to calculate things.
to the TX closed-loop power control registers.
* Modify a couple of functions to take the register chain number,
rather than the regChainOffset value. This allows for the
register chain to be logged.
Linux ath9k.
The ath9k ar9002_hw_init_cal() isn't entirely clear about what
is supposed to be called for what chipsets, so I'm ignoring the
rest of it and just porting the AR9285 init cal path as-is and
leaving the rest alone. Subsequent commits may also tidy up the
Merlin (AR9285) and other chipset support.
Obtained from: Linux ath9k
