* The AR_ISR_RAC interrupt processing method has a subtle bug in all
the MAC revisions (including pre-11n NICs) until AR9300v2.
If you're unlucky, the clear phase clears an update to one of the
secondary registers, which includes TX status.
This shows up as a "watchdog timeout" if you're doing very low levels
of TX traffic. If you're doing a lot of non-11n TX traffic, you'll
end up receiving a TX interrupt from some later traffic anyway.
But when TX'ing 11n aggregation session traffic (which -HEAD isn't yet
doing), you may find that you're only able to TX one frame (due to
BAW restrictions) and this may end up hitting this race condition.
The only solution is to not use RAC and instead use AR_ISR and the
AR_ISR_Sx registers. The bit in AR_ISR which represents the secondary
registers are not cleared; only the AR_ISR_Sx bits are. This way
any updates which occur between the read and subsequent write will
stay asserted and (correctly) trigger a subsequent interrupt.
I've tested this on the AR5416, AR9160, AR9280. I will soon test
the AR9285 and AR9287.
* The AR_ISR TX and RX bits (and all others!) are set regardless of
whether the contents of the AR_IMR register. So if RX mitigation is
enabled, RXOK is going to be set in AR_ISR and it would normally set
HAL_INT_RX.
Fix the code to not set HAL_INT_RX when RXOK is set and RX mitigation
is compiled in. That way the RX path isn't prematurely called.
I would see:
* An interrupt would come in (eg a beacon, or TX completion) where
RXOK was set but RXINTM/RXMINT wasn't;
* ath_rx_proc() be called - completing RX frames;
* RXINTM/RXMINT would then fire;
* ath_rx_proc() would then be called again but find no frames in the
queue.
This fixes the RX mitigation behaviour to not overly call ath_rx_proc().
* Start to flesh out more correct timer interrupt handling - it isn't
kite/merlin specific. It's actually based on whether autosleep support
is enabled or not.
This is sourced from my 11n TX branch and has been tested for a few weeks.
Finally, the interrupt handling change should likely be implemented
for AR5210, AR5211 and AR5212.
There are some timing concerns which I've yet to fully map out.
In any case, there's an existing software driven mitigation method
for TX interrupts and when TX'ing 11n frames, the whole frame itself
generates an interrupt rather then the subframes.
Although I tried to fix this earlier by introducing HALDEBUG_G(), it
turns out there seem to be other cases where the pointer value is still
NULL.
* Fix DO_HALDEBUG() and the HALDEBUG macro to check whether ah is NULL
before deferencing it
* Remove HALDEBUG_G() as it's no longer needed
This is hopefully a merge candidate for 9.0-RELEASE as enabling
debugging at startup could result in a kernel panic.
rather than the whole beacon interval.
The reference driver and Linux ath9k both choose 80% of the
beacon interval and they do it in the driver rather than
the HAL (Ath reference) or ath9k_hw (ath9k.)
This quietens stuck beacon conditions on my AR9220/AR9280
based NICs when a lot of burst broadcast/multicast traffic
is going on. It doesn't seem to annoy the earlier MACs as
much as the AR9280 and later one.
Obtained from: Linux ath9k, Atheros
local variable with a beacon interval of 100 TU. This never gets modified
if the beacon interval configuration changes.
This may have been correct in earlier times, but with the advent of
staggered beacons (which default to 1 / ATH_BCBUF beacon interval, so
25 TU here) this value is incorrect.
It is used to configure the default CABQ readytime. So here, the cabq
was being configured to be much greater than the target beacon timer
(TBTT.)
The driver should be configuring a cabq readytime value rather then
leaving it to the HAL to choose sensible defaults. This should be
done in the future - I'm simply trying to ensure sensible defaults
are chosen.
This is another commit in a series of TDMA support fixes for the 11n NICs.
* Move ath_hal_getnexttbtt() into the HAL; write methods for it.
This returns a timer value in TSF, rather than TU.
* Move ath_hal_getcca() and ath_hal_setcca() into the HAL too, where they
likely now belong.
* Create a new HAL capability: HAL_CAP_LONG_RXDESC_TSF.
The pre-11n NICs write 15 bit TSF snapshots into the RX descriptor;
the AR5416 and later write 32 bit TSF snapshots into the RX descriptor.
* Use the new capability to choose between 15 and 31 bit TSF adjustment
functions in ath_extend_tsf().
* Write ar5416GetTsf64() and ar5416SetTsf64() methods.
ar5416GetTsf64() tries to compensate for TSF changes at the 32 bit boundary.
According to yin, this fixes the TDMA beaconing on 11n chipsets and TDMA
stations can now associate/talk, but there are still issues with traffic
stability which need to be investigated.
The ath_hal_extendtsf() function is also used in RX packet timestamping;
this may improve adhoc mode on the 11n chipsets. It also will affect the
timestamps seen in radiotap frames.
Submitted by: Kang Yin Su <cantona@cantona.net>
Approved by: re (kib)
reference driver does clear the async interrupts after each service.
I'll tinker with this in a future commit.
Obtained from: Atheros
Approved by: re (kib)
When the fast clock (44mhz) is enabled for 5ghz HT20, the
dual ADCs aren't enabled. Trying to do the ADC calibrations
here would result in calibration never completing; this
resulted in IQ calibration never running and thus performance
issues in 11a/11n HT20 mode.
Leave it enabled for non-fastclock (40mhz) 11a mode and
HT40 modes.
This has been fixed in discussion with Felix Fietkau (nbd)
and discussions with the Atheros baseband team.
Linux ath9k now has a similar fix.
Approved by: re (kib)
The AR5212 HAL didn't check this field; timers are enabled a different
way.
The AR5416 HAL however did, and since this field was uninitialised, it had
whatever was on the stack at the time. This lead to "unpredictable"
behaviour.
This allows TDMA to work on the AR5416 and later chipsets.
Thanks to: paradyse@gmail.com
Approved by: re (kib, blanket)
* Fix SLEEP1/SLEEP2 register definitions; the CAB/Beacon timeout
fields have changed in AR5416 and later
* The TIM_PERIOD and DTIM_PERIOD registers are now microsecond fields,
not TU.
Obtained from: Linux ath9k, Atheros reference
Approved by: re (kib, blanket)
or later. Previous hardware had some as TU, some as 1/8th
TU.
* Modify AR_NEXT_DBA and AR_NEXT_SWBA to use a new macro,
ONE_EIGHTH_TU_TO_USEC(), which converts the 1/8th TU
fields to USEC. This is just cosmetic and matches the
Atheros reference driver.
* Fix AR_NEXT_TBTT, which is USEC, not TU.
Submitted by: paradyse@gmail.com
Approved by: re (kib, blanket)
needing this particular modification.
It can be called during ath_dfs_radar_enable() and still achieve the
same functionality, so I am.
Approved by: re (kib, blanket)
Remove this debugging, it's not needed anymore and when not enabled,
those variables trigger a compiler warning.
Approved by: re (kib, blanket)
Pointy-hat-to: adrian, for not testing a non-debug compile of this code enough
allows it to be overridden at runtime.
Thus, add a function which updates ah_dfsDomain after a channel set
call to ath_hal_set_channels().
Approved by: re (kib, blanket)
and the Atheros reference code.
The radar detection code needs to know what the current DFS domain is.
Since net80211 doesn't currently know this information, it's extracted
from the HAL regulatory domain information.
The specifics:
* add a new ath_dfs API hook, ath_dfs_init_radar_filters(), which
updates the radar filters whenever the regulatory domain changes.
* add HAL_DFS_DOMAIN which describes the currently configured DFS domain .
* add a new HAL internal variable which tracks the currently configured
HAL DFS domain.
* add a new HAL capability, HAL_CAP_DFS_DMN, which returns the currently
configured HAL DFS domain setting.
* update the HAL DFS domain setting whenever the channel setting is
updated.
Since this isn't currently used by any radar code, these should all
be no-ops for existing users.
Obtained from: Atheros
Submitted by: KBC Networks, sibridge
Approved by: re (kib, blanket)
if 5ghz fast clock is enabled in the current operating mode.
It's slightly dirty, but it's part of the reference HAL and used by
the (currently closed-source) radar event code to map radar pulses
back to microsecond durations.
Obtained from: Atheros
Approved by: re (kib, blanket)
the ar9130 code.
Since at least one kernel config specifies individual ath HAL chips
rather than just "device ath_hal" (arm/AVILA), I'm doing this so people
aren't caught out when they update to -HEAD or 9.0 and discover their
ath setup doesn't compile.
I'll revisit this with a proper fix sometime before 9.0-RELEASE.
Approved by: re (kib, blanket)
Pointed out by: ray@
Pointy hat to: adrian@
systems, in the same way that AR9130 embedded systems work.
This isn't -everything- that is required - the PCI glue still
needs to be taught about the eepromdata hint, along the same
lines as the AHB glue.
Approved by: re (kib, blanket)
truly.
Before 802.11n, the RX descriptor list would employ the "self-linked tail
descriptor" trick which linked the last descriptor back to itself.
This way, the RX engine would never hit the "end" of the list and stop
processing RX (and assert RXEOL) as it never hit a descriptor whose next
pointer was 0. It would just keep overwriting the last descriptor until
the software freed up some more RX descriptors and chained them onto the
end.
For 802.11n, this needs to stop as a self-linked RX descriptor tickles the
block-ack logic into ACK'ing whatever frames are received into that
self-linked descriptor - so in very busy periods, you could end up with
A-MPDU traffic that is ACKed but never received by the 802.11 stack.
This would cause some confusion as the ADDBA windows would suddenly
be out of sync.
So when that occured here, the last descriptor would be hit and the PCU
logic would stop. It would only start again when the RX descriptor list
was updated and the PCU RX engine was re-tickled. That wasn't being done,
so RXEOL would be continuously asserted and no RX would continue.
This patch introduces a new flag - sc->sc_kickpcu - which when set,
signals the RX task to kick the PCU after its processed whatever packets
it can. This way completed packets aren't discarded.
In case some other task gets called which resets the hardware, don't
update sc->sc_imask - instead, just update the hardware interrupt mask
directly and let either ath_rx_proc() or ath_reset() restore the imask
to its former setting.
Note: this bug was only triggered when doing a whole lot of frame snooping
with serial console IO in the RX task. This would defer interrupt processing
enough to cause an RX descriptor overflow. It doesn't happen in normal
conditions.
Approved by: re (kib, blanket)
interrupt storm.
This is easily triggered by flipping on and off tcpdump -y IEEE802_11_RADIO
w/ witness enabled. This causes a whole lot of console IO and when you're
attached to a serial console (eg on my AR7161 embedded board), the RX
interrupt doesn't get called quickly enough and the RX queue fills up.
This wasn't a problem in the past because of the self-linked RX descriptor
trick - the RX would never hit the "end" of the RX descriptor list.
However this isn't possible for 802.11n (see previous commit history for
why.)
Both Linux ath9k and the Atheros reference driver code do this; I'm just
looking now for where they then restart the PCU receive. Right now the RX
will just stop until the interface is reset.
Obtained from: Linux, Atheros
Approved by: re (kib)
The AR9280 apparently has an issue with descriptors which straddle a page
boundary (4k). I'm not yet sure whether I should use PAGE_SIZE in the
calculations or whether I should use 4096; the reference code uses 4096.
This patch fiddles with descriptor allocation so a descriptor entry
doesn't straddle a 4kb address boundary. The descriptor memory allocation
is made larger to contain extra descriptors and then the descriptor
address is advanced to the next 4kb boundary where needed.
I've tested this both on Merlin (AR9280) and non-Merlin (in this case,
AR9160.)
Obtained from: Linux, Atheros
Approved by: re (kib)
This seems to indicate whether to program the NIC for fractional 5ghz
mode (ie, 5mhz spaced channels, rather than 10 or 20mhz spacing) or not.
The default (0) seems to mean "only program fractional mode if needed".
A different value (eg 1) seems to always enable fractional 5ghz mode
regardless of the frequency.
Obtained from: Atheros
Approved by: re (kib)
Calibration/PCI data that's written to flash (rather than EEPROM attached
to the NIC) is typically already in host-endian. The existing checks
end up swapping 16 bit words incorrectly - the correct solution would be
to read the magic value and determine the EEPROM endianness from that.
(This is what Linux does.)
This doesn't completely enable embedded use of the AR9285/AR9287 -
notably, the EEPROM read methods need to be made generic and available
to all EEPROM drivers. I'll worry about that later.
Approved by: re (kib)
* I messed up the order of parameter true/false; oops!
* AR_PHY_RADAR_1 was being written at the wrong place, and was writing
potential garbage to the hardware.
Approved by: re (kib)
* Teach the AR5212/AR5416 ANI code to use the RX filter methods, rather
than calling the RX filter routines directly.
* Make HAL_ANI_PRESENT and HAL_ANI_MODE unconditionally available,
regardless of whether ah_ani_function is masking it.
* (Mostly) fully disable ANI if interference mitigation is disabled.
When disabled, the ANI code doesn't touch any ANI/PHY registers,
leaving them the default value. This is in line with what the
Atheros reference driver does.
* Correctly set the ANI parameters during ANI reset, rather than
when ANI is enabled. In this way, if ANI is disabled or enabled
whilst the NIC is not active (and there's no current channel),
bogus parameters or a NULL pointer deference doesn't occur.
There's still some lingering issues - notably, the MIB events/interrupts
aren't fully disabled, so MIB interrupts still occur. I'll worry about
that later.
Approved by: re (kib)
This in particular fixes radar PHY handling - on the AR5212
NIC, one enables the AR_PHY_ERR_RADAR bit in AR_PHY_ERR;
the AR5416 and later also needs a bit set in AR_RX_FILTER.
A follow-up commit is needed to convert the AR5416 ANI code
to use this particular method, as it's currently using the
AR5212 methods directly.
Obtained from: Atheros
Approved by: re (kib)
the ADC calibrations if the NIC is in 5ghz 11a or 5ghz HT/20 modes.
I've been told that the dual-ADC is only engaged in turbo/40mhz modes.
Since Sowl (AR9160) seems to return valid-looking calibration data
in 5ghz 20MHz modes, I'm only disabling it for Merlin for now.
It may turn out I can disable it for all chipsets and only enable
it for 40MHz modes.
Approved by: re (kib)
It looks like this was mixed up with the AR9285 calibration code.
This code is now more in line with what Linux ath9k and Atheros
reference drivers do.
Obtained from: Atheros
Approved by: re (kib)
Although this may not be what the original sysctl was designed to do,
it feels a bit more "expected".
Before, if ANI is disabled, the initial ANI parameters are still written
to the hardware, even if they're not enabled. "ANI enabled" would then
adjust the noise immunity parameters dynamically. Disabling ANI would
simply leave the existing noise immunity parameters where they are,
and disable the dynamic part.
The problem is that disabling ANI doesn't leave the hardware in
a consistent, predictable state - so asking a user to disable ANI
wouldn't actually reset the NIC to a consistent set of PHY signal
detection parameters, resulting in an unpredictable/unreliable outcome.
This makes it difficult to get reliable debugging information from
the user.
Approved by: re (kib)
