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.
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.
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.
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.
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.
