and interface resets to be marked as ATH_RESET_DEFAULT, ATH_RESET_FULL,
ATH_RESET_NOLOSS.
Currently a reset is still a reset - ie, all tx/rx frames in the hardware
queues are purged. This means that those frames will be lost to the 11n TX
and RX aggregation state tracking, breaking AMPDU sessions.
The (eventual) new semantics:
* ATH_RESET_DEFAULT:
full reset, this is the default for reset situations
which I haven't yet figured out what they should be.
* ATH_RESET_FULL:
A full reset - for things such as channel changes.
* ATH_RESET_NOLOSS:
Don't flush TX/RX queues - handle pending RX frames and leave TX
frames where they are; restart TX DMA from where it was.
* Change ath_rx_proc() to ath_rx_tasklet(); make that the taskqueue function.
This way (eventually) ath_rx_proc() can be called from elsewhere in the
packet reset/processing queue so frames aren't just "flushed" during
interface resets/reconfigure. This breaks 802.11n RX aggregation tracking.
* Extend ath_tx_proc() to take a 'resched' flag, which marks whether to
reschedule further RX PCU reads or not.
* Change ath_tx_processq() to take a "dosched" flag, which will eventually
be used to indicate whether to reschedule the software TX scheduler.
Sponsored by: Hobnob, Inc.
* Close down some of the kickpcu races, where the interrupt handler
can and will run concurrently with the taskqueue.
* Close down the TXQ active/completed race between the interrupt
handler and the concurrently running tx completion taskqueue
function.
* Add some tx and rx interrupt count tracking, for debugging.
* Fix the kickpcu logic in ath_rx_proc() to not simply drain and
restart the TX queue - instead, assume the hardware isn't
(too) confused and just restart RX DMA. This may break on
previous chipsets, so if it does I'll add a HAL flag and
conditionally handle this (ie, for broken chipsets, I'll
just restore the "stop PCU / flush things / restart PCU"
logic.)
* Misc stuff
Sponsored by: Hobnob, Inc.
A bunch of the 11n TX aggregation logic wants to traverse lists of buffers
in various ways. In order to provide O(1) behaviour in this instance,
use TAILQs.
This does blow out the memory footprint and CPU cycles slightly for some
of these operations. I may convert some of these back to STAILQs once
the rest of the software transmit queue handling has been stabilised.
Sponsored by: Hobnob, Inc.
* Use 64 bit integer types for the sample rate statistics.
When TX'ing 11n aggregates, a 32 bit counter will overflow in a few
hours due to the high packet throughput.
* Create a default label of "" rather than defaulting to "Mb" - that way
if a rate hasn't yet been selected, it won't say "-1 Mb".
Sponsored by: Hobnob, Inc.
* Add a PCU lock, which isn't currently used but will eventually be
used to serialise some of the driver access.
* Add in all the software TX aggregation state, that's kept per-node
and per-TID.
* Add in the software and aggregation state to ath_buf.
* Add in hooks to ath_softc for aggregation state and the (upcoming)
aggregation TX state calls.
* Add / fix the HAL access macros.
Obtained from: Linux, ath9k
Sponsored by: Hobnob, Inc.
The SYSCTL_NODE macro defines a list that stores all child-elements of
that node. If there's no SYSCTL_DECL macro anywhere else, there's no
reason why it shouldn't be static.
their length.
Without this, an error frame mbuf would:
* have its size adjusted;
* thrown at the radiotap code;
* then since it's never consumed, the rxbuf/mbuf is then re-added to the
RX descriptor list with the small size;
* .. and the hardware ends up (sometimes) only DMA'ing part of a frame into
the small buffer, chaining RX frames together (setting the more flag).
I discovered this particular issue when doing some promiscuous radiotap
testing; I found that I'd occasionally get rs_more set in RX descriptors
w/ the first frame length being very small (sub-100 bytes.) The driver
handles 2-descriptor RX frames (but not more), so this still worked; it
was just odd.
This is suboptimal and may benefit from being replaced with caching
the m_pkthdr_len and m_len fields, then restoring them after completion.
* preserve AR_TxIntrReq on every descriptor in an aggregate chain,
not just the first descriptor;
* always blank out the descriptor in ar5416ChainTxDesc() when forming
aggregates - the way I'm using this in the 11n branch is to first
chain aggregates together, then use the other HAL calls to fill in
the details.
* Add the TID field in the TX status descriptor;
* Add in the 11n first/middle/last functions for fiddling
with the descriptors. These are from the Linux and the
reference driver, but I'm not (currently) using them.
* Add further AR_ISR_S5 register definitions.
Obtained from: Linux ath9k, Atheros
interfere with traffic, as the NF load can take quite a while and poking the
AGC every 10uS is just a bit silly.
Instead, just leave the baseband NF calibration where it is and just read it
back next time a longcal interval happens.
Some earlier series (~AR5212?) play badly with BIOSes.
In these instances, they may require a forced reset (by transitioning
the NIC through D0 -> D3 -> D0) before they probe/attach correctly.
This is currently disabled because:
* I haven't figured out the "right" code to ensure this only happens
for PCI NICs (not PCIe or Cardbus);
* I haven't at all done wide scale testing for this, and I'm not yet
ready for said wide-scale testing.
I'm documenting this primarily so users with misbehaving NICs have
something to tinker with.
Obtained from: Atheros
The final missing bit here is enabling the PCI configuration register
read, but there's currently no glue available for the HAL to read (and
write) PCI configuration space registers.
Obtained from: Atheros
The AR5008/AR9001 series NICs have a bug where BB register reads
will occasionally be corrupted. This could cause issues with things
such as ANI, which adjust operational parameters based on the
BB radio register reads. This was introduced in the AR5008 chip
and fixed with the first released AR9002 series NIC (AR9280v2.)
A followup commit will implement the acutal WAR when reading
BB registers. I'm still not sure how I'll implement it - whether
it should be done in the osdep layer, or whether it should just
live in the AR5416 HAL. Either way, they can use this capability
bit to determine whether to implement the WAR or not.
Thankyou to various sources inside Atheros who have helped me track
down what this particular issue is.
Obtained from: Atheros
There are HAL methods which are actually direct register
access, rather than simply HAL calls. Because of this, these
register accesses would use the non-debug path in ah_osdep.h
as opt_ah.h isn't included.
With this, the correct register access methods are used,
so debugging traces show things such as TXDP checking and
TSF32 access.
That way the radar errors aren't enabled prematurely.
A DFS tester has reported that radar events are reported
during channel scanning, before DFS is actually enabled.
* Break out the PCI setup override code into a new function.
* Re-apply the PCI overrides on powersave resume. The retry timeout
register isn't currently being saved/resumed by the PCI driver/bus
code.
Pre-11n devices and AR5416 use AR_PHY(263) for current RX RSSI.
AR9130 and later have a fourth calibration register (for doing
ADC calibration) and thus the register has moved to AR_PHY(271).
This isn't currently used by any of the active code; I'm committing
this for completeness and in case any third party code attempts to
use it for legacy reasons.
* 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)
