in the HAL. That's very memory hungry (32k just for channel statistics)
which would be better served by keeping a summary in the ANI state.
Or, later, keep a survey history in net80211.
So:
* Migrate the ah_chansurvey array to be a single entry, for the current
channel.
* Change the ioctl interface and ANI code to just reference that.
* Clear the ah_chansurvey array during channel reset, both in the AR5212
and AR5416 reset path.
* Always call ar5416GetListenTime()
* Modify ar5416GetListenTime() to:
+ don't update the ANI state if there isn't any ANI state;
+ don't update the channel survey state if there's no active
channel - just to be paranoid
+ copy the channel survey results into the current sample slot
based on the current channel; then increment the sample counter
and sample history counter.
* Modify ar5416GetMIBCyclesPct() to simply return a HAL_SURVEY_SAMPLE,
rather than a set of percentages. The ANI code wasn't using the
percentages anyway.
TODO:
* Create a new function which fetches the survey results periodically
* .. then modify the ANI code to use the pre-fetched values rather than
fetching them again
* Roll the 11n ext busy function from ar5416_misc.c to update all the
counters, then do the result calculation
* .. then, modify the MIB counter routine to correctly fetch a snapshot -
freeze the counters, fetch the values, then reset the counters.
The reference driver has a 3ms delay for the AR9130 but I'm not as yet
sure why. From what I can gather, it's likely waiting for some FIFO
flush to occur.
At some point in the future it may be worthwhile adding a WMAC
FIFO flush here, but that'd require some side-call through to the SoC
DDR flush routines.
Obtained from: Atheros
which will be needed for AR7010 and AR9287 USB access.
The names differ slightly from Linux and Atheros, for the sake of
consistency.
A lot more work is required in order to convert the 11n HAL support to
fully support USB.
at least until I can root cause what's going on.
The only platform I've seen this on is the AR9220 when attached to
the AR71xx CPUs. I get immediate PCIe bus errors and all subsequent
accesses cause further MIPS bus exceptions. I don't have any other
big-endian platforms to test this on.
If I get a chance (or two), I'll try to whack this on a bus analyser
and see exactly what happens.
I'd rather leave this on, especially for slower, embedded platforms.
But the #ifdef hell is something I'm trying to avoid.
This may result in a bit of a throughput drop. However, any throughput
drop at this point should be investigated and root caused, as it's likely
because TX scheduling (all the way down to how preemption, scheduler work,
etc) is happening in a sub-optimal fashion.
This also makes it much more likely to be reloadable on a live machine.
Allocating 5120 TX ath_buf entries via contigmalloc is very unlikely
after a few hours of using X/Chromium.
dirty and murky past.
* Override the default cache line size to be something reasonable if
it's set to 0. Some NICs initialise with '0' (eg embedded ones)
and there are comments in the driver stating that various OSes (eg
older Linux ones) would incorrectly program things and 0 out this
register.
* Just default to overriding the latency timer. Every other driver
does this.
* Use a default cache line size of 32 bytes. It should be "reasonable
enough".
Obtained from: Linux ath9k, Atheros
interface.
* Introduce a device hint, 'eeprom_firmware', which is the name of firmware
to lookup.
* If the lookup succeeds, take a copy of it and use it as the eeprom data.
This isn't enabled by default - you have to define ATH_EEPROM_FIRMWARE.
I'll add it to the configuration variables in a later commit.
TODO:
* just keep a firmware reference in ath_softc, and remove the need to
waste the extra memory in having sc_eepromdata be a malloc()ed block.
add a FreeBSD_version check. It should work fine for compiling
on -HEAD, 9.x and 8.x.
* Conditionally compile the 11n options only when 11n is enabled.
The above changes allow the ath(4) driver to compile and run on
8.1-RELEASE (Hi old PC-BSD!) but with the 11n stuff disabled.
I've done a test against the net80211 and tools in 8.1-RELEASE.
The NIC used in testing is the AR2427 in an EEEPC.
Just to be clear - this change is to allow the -HEAD ath/hal/rate
code to run on 9.x _and_ 8.x with no source changes. However,
when running on earlier kernels, it should only be used for legacy
mode. (Don't define ATH_ENABLE_11N.)
damage which I committed when I had less clue about such things.
Don't ever put normal data frames on the mcast software queue.
Just put mcast frames there if needed.
Pass the txq decision into ath_tx_normal_setup(), as we've already made
the decision. Don't re-do it.
Whilst i'm here, add another random debugging statement.
call these after rate control selection is done.
The duration/protection code wasn't working - it expected the rix to
be valid. Unfortunately after I moved the rate control selection into
late in the process, the rix value isn't valid and thus the protection/
duration code would get things wrong.
HT frames are now correctly protected with an RTS and for the AR5416,
this involves having the aggregate frames be limited to 8K.
TODO:
* Fix up the DMA sync to occur just before the frame is queued to the
hardware. I'm adjusting the duration here but not doing the DMA
flush.
* Doubly/triply ensure that the aggregate frames are being limited to
the correct size, or the AR5416 will get unhappy when TXing RTS-protected
aggregates.
if any subframes in an aggregate have different protection from the
first frame in the formed aggregate, don't add that frame to the
aggregate.
This is likely a suboptimal method (I think we'll mostly be OK marking
frames that have seqno's with the same protection as normal data frames)
but I'll just be cautious for now.
This will be used by some upcoming code to ensure that aggregates
are enforced to be a certain size. The AR5416 has a limitation on
RTS protected aggregates (8KiB).
A BAR frame must be transmitted when an frame in an A-MPDU session fails
to transmit - it's retried too often, or it can't be cloned for
re-transmission. The BAR frame tells the remote side to advance the
left edge of the block-ack window (BAW) to a new value.
In order to do this:
* TX for that particular node/TID must be paused;
* The existing frames in the hardware queue needs to be completed, whether
they're TXed successfully or otherwise;
* The new left edge of the BAW is then communicated to the remote side
via a BAR frame;
* Once the BAR frame has been sucessfully TXed, aggregation can resume;
* If the BAR frame can't be successfully TXed, the aggregation session
is torn down.
This is a first pass that implements the above. What needs to be done/
tested:
* What happens during say, a channel reset / stuck beacon _and_ BAR
TX. It _should_ be correctly buffered and retried once the
reset has completed. But if a bgscan occurs (and they shouldn't,
grr) the BAR frame will be forcibly failed and the aggregation session
will be torn down.
Yes, another reason to disable bgscan until I've figured this out.
* There's way too much locking going on here. I'm going to do a couple
of further passes of sanitising and refactoring so the (re) locking
isn't so heavy. Right now I'm going for correctness, not speed.
* The BAR TX can fail if the hardware TX queue is full. Since there's
no "free" space kept for management frames, a full TX queue (from eg
an iperf test) can race with your ability to allocate ath_buf/mbufs
and cause issues. I'll knock this on the head with a subsequent
commit.
* I need to do some _much_ more thorough testing in hostap mode to ensure
that many concurrent traffic streams to different end nodes are correctly
handled. I'll find and squish whichever bugs show up here.
But, this is an important step to being able to flip on 802.11n by default.
The last issue (besides bug fixes, of course) is HT frame protection and
I'll address that in a subsequent commit.
Linux ath9k doesn't have this issue as it doesn't try queuing multi-
descriptor frames to the hardware.
Before, I was only setting the first and last descriptor in the final
frame correctly - and that was done by accident. The first descriptor in
the last sub-frame was being correctly updated by ath_tx_setds_11n();
the last descriptor in the last sub-frame was being correctly updated
by ath_buf_set_rate(). But both of those are "incorrect".
The correct behaviour is:
* AR_IsAggr is set for all descriptors for all subframes in an aggregate.
* AR_MoreAggr is set for all descriptors for all non-final sub-frames
in an aggregate.
Ie, all descriptors in the last sub-frame of an aggregate must have this
field set to 0.
I still need to do a couple of extra passes to ensure the pad delimiter
field is being correctly handled in all descriptors in the last sub-frame.
Right now ath_txq_sched() is mainly called from the TX ath_tx_processq()
routine, which is (mostly) done as part of the taskqueue. It shouldn't
be called outside the taskqueue.
But now that I'm about to flip back on BAR TX, I'm going to start
stressing the ath_tx_tid_pause() and ath_tx_tid_resume() paths.
What I don't want to have happen is a reschedule of the TID traffic
_during_ the completion of TX frames.
Ideally I'd like to have a way to flag back up to the processing code
that the current hardware queue should be rechecked for software TID
queue frames. But for now, this should suffice for the BAR TX case.
I may eventually delete this code once I've brought some further
sanity to the general TX queue/completion path.
within the BAW.
This regression was introduced in ane earlier commit by me to fix the
BAW seqno allocation-but-not-insertion-into-BAW race. Since it was only
ever using the to-be allocated sequence number, any frame retries
with the first frame in the BAW still in the software queue would
have constantly failed, as ni_txseqs[tid] would always be outside
the BAW.
TODO:
* Extract out the mostly common code here in the agg and non-agg ADDBA
case and stuff it into a single function.
PR: kern/166357
I see traffic stalls.
It turns out that the bug isn't because the first and last frame in the
BAW is in the software queue. It is more likely that it's because
the first frame in the BAW is still in the software queue and thus there's
no more room to allocate and do subsequent TX.
PR: kern/166357
This is not entirely correct as it simply resets the channel, flushing
whatever is in the TX/RX queue. This can and will break aggregation
BAW tracking. But the alternative (HT40 frames being sent with the hardware
in HT20 mode) is even worse.
There's still a small window between the htinfo being received (and the ni_chw
field being updated) which could cause problems. I'll look at fleshing this
out in follow-up commits.
PR: kern/166286
