Right now ath_rate_sample has a fixed rate schedule, rather than the minstrel_ht
style "best, good, most reliable" triplet. So, if higher rates are tried then
it'll not fail back to a lower MCS rate in that transmission schedule.
This means that in low SNR situations it'll not easily drop to MCS0 unless enough
transmissions occur to allow rate control to eventually decide to drop; and if
it's TCP traffic it'll get slowed down because of packet loss.
It's worse for 2-stream and 3-stream rates; it doesn't ever fall back to lower
stream rates, and these higher stream rates required higher SNR to work.
So instead let's (for now?) have each of the 11n transmit rates use MCS0 as
the last attempt. ath_rate_sample will quickly see that rate succeeds more
and will move to it much quicker.
Testing:
* AR9344 (Wasp) - 2G STA mode
These are some fun issues I've found with my upstairs wifi link at such a ridiculous
low signal level (like, < 5dB.)
* Add per-station tx/rx rssi statistics, in potential preparation to use that
in the RX rate control.
* Call the rate control on each received frame to let it potentially use
it as a hint for what rates to potentially use. It's a no-op right now.
* Do ANI calibration during scan as well. The ath_newstate() call was disabling the
ANI timer and only re-enabling it during transitions to _RUN. This has the
unfortunate side-effect that if ANI deafened the NIC because of interference
and it disassociated, it wouldn't be reset and the scan would never hear beacons.
The ANI configuration is stored at least globally on some HALs and per-channel
on others. Because of this a NIC reset wouldn't help; the ANI parameters would
simply be programmed back in.
Now, I have a feeling I also need to do this during AUTH/ASSOC too and maybe,
if I'm feeling clever, I need to reset the ANI parameters on a given channel
during a transition through INIT or if the VAP is destroyed/re-created.
However for now this gets me out of the immediate weeds with connectivity
upstairs (and thus I /can/ commit); I'll keep chipping away at tidying this
stuff up in subsequent commits.
Tested:
* AR9344 (Wasp), 2G STA mode
Mainly focus on files that use BSD 2-Clause license, however the tool I
was using misidentified many licenses so this was mostly a manual - error
prone - task.
The Software Package Data Exchange (SPDX) group provides a specification
to make it easier for automated tools to detect and summarize well known
opensource licenses. We are gradually adopting the specification, noting
that the tags are considered only advisory and do not, in any way,
superceed or replace the license texts.
In the deep past, when this code compiled as a binary module, ath_hal
built as a module. This allowed custom, smaller HAL modules to be built.
This was especially beneficial for small embedded platforms where you
didn't require /everything/ just to run.
However, sometime around the HAL opening fanfare, the HAL landed here
as one big driver+HAL thing, and a lot of the (dirty) infrastructure
(ie, #ifdef AH_SUPPORT_XXX) to build specific subsets of the HAL went away.
This was retained in sys/conf/files as "ath_hal_XXX" but it wasn't
really floated up to the modules themselves.
I'm now in a position where for the reaaaaaly embedded boards (both the
really old and the last couple generation of QCA MIPS boards) having a
cut down HAL module and driver loaded at runtime is /actually/ beneficial.
This reduces the kernel size down by quite a bit. The MIPS modules look
like this:
adrian@gertrude:~/work/freebsd/head-embedded/src % ls -l ../root/mips_ap/boot/kernel.CARAMBOLA2/ath*ko
-r-xr-xr-x 1 adrian adrian 5076 May 23 23:45 ../root/mips_ap/boot/kernel.CARAMBOLA2/ath_dfs.ko
-r-xr-xr-x 1 adrian adrian 100588 May 23 23:45 ../root/mips_ap/boot/kernel.CARAMBOLA2/ath_hal.ko
-r-xr-xr-x 1 adrian adrian 627324 May 23 23:45 ../root/mips_ap/boot/kernel.CARAMBOLA2/ath_hal_ar9300.ko
-r-xr-xr-x 1 adrian adrian 314588 May 23 23:45 ../root/mips_ap/boot/kernel.CARAMBOLA2/ath_main.ko
-r-xr-xr-x 1 adrian adrian 23472 May 23 23:45 ../root/mips_ap/boot/kernel.CARAMBOLA2/ath_rate.ko
And the x86 versions, like this:
root@gertrude:/home/adrian # ls -l /boot/kernel/ath*ko
-r-xr-xr-x 1 root wheel 36632 May 24 18:32 /boot/kernel/ath_dfs.ko
-r-xr-xr-x 1 root wheel 134440 May 24 18:32 /boot/kernel/ath_hal.ko
-r-xr-xr-x 1 root wheel 82320 May 24 18:32 /boot/kernel/ath_hal_ar5210.ko
-r-xr-xr-x 1 root wheel 104976 May 24 18:32 /boot/kernel/ath_hal_ar5211.ko
-r-xr-xr-x 1 root wheel 236144 May 24 18:32 /boot/kernel/ath_hal_ar5212.ko
-r-xr-xr-x 1 root wheel 336104 May 24 18:32 /boot/kernel/ath_hal_ar5416.ko
-r-xr-xr-x 1 root wheel 598336 May 24 18:32 /boot/kernel/ath_hal_ar9300.ko
-r-xr-xr-x 1 root wheel 406144 May 24 18:32 /boot/kernel/ath_main.ko
-r-xr-xr-x 1 root wheel 55352 May 24 18:32 /boot/kernel/ath_rate.ko
.. so you can see, not building the whole HAL can save quite a bit.
For example, if you don't need AR9300 support, you can actually avoid
wasting half a megabyte of RAM. On embedded routers this is quite a
big deal.
The AR9300 HAL can be later further shrunk because, hilariously,
it indeed supports AH_SUPPORT_<xxx> for optionally adding chipset support.
(I'll chase that down later as it's quite a big savings if you're only
building for a single embedded target.)
So:
* Create a very hackish way to load/unload HAL modules
* Create module metadata for each HAL subtype - ah_osdep_arXXXX.c
* Create module metadata for ath_rate and ath_dfs (bluetooth is
currently just built as part of it)
* .. yes, this means we could actually build multiple rate control
modules and pick one at load time, but I'd rather just glue this
into net80211's rate control code. Oh well, baby steps.
* Main driver is now "ath_main"
* Create an "if_ath" module that does what the ye olde one did -
load PCI glue, main driver, HAL and all child modules.
In this way, if you have "if_ath_load=YES" in /boot/modules.conf
it will load everything the old way and stuff should still work.
* For module autoloading purposes, I actually /did/ fix up
the name of the modules in if_ath_pci and if_ath_ahb.
If you want to selectively load things (eg on ye cheape ARM/MIPS platforms
where RAM is at a premium) you should:
* load ath_hal
* load the chip modules in question
* load ath_rate, ath_dfs
* load ath_main
* load if_ath_pci and/or if_ath_ahb depending upon your particular
bus bind type - this is where probe/attach is done.
TODO:
* AR5312 module and associated pieces - yes, we have the SoC side support
now so the wifi support would be good to "round things out";
* Just nuke AH_SUPPORT_AR5416 for now and always bloat the packet
structures; this'll simplify other things.
* Should add a simple refcnt thing to the HAL RF/chip modules so you
can't unload them whilst you're using them.
* Manpage updates, UPDATING if appropriate, etc.
The pre-11n calculations include SIFS, but the 11n ones don't.
The reason is that (mostly) the 11n hardware is doing the SIFS calculation
for us but the pre-11n hardware isn't. This means that we're over-shooting
the times in the duration field for non-11n frames on 11n hardware, which
is OK, if not a little inefficient.
Now, this is all fine for what the hardware needs for doing duration math
for ACK, RTS/CTS, frame length, etc, but it isn't useful for doing PHY
duration calculations. Ie, given a frame to TX and its timestamp, what
would the end of the actual transmission time be; and similar for an
RX timestamp and figuring out its original length.
So, this adds a new field to the duration routines which requests
SIFS or no SIFS to be included. All the callers currently will call
it requesting SIFS, so this /should/ be a glorious no-op. I'm however
planning some future work around airtime fairness and positioning which
requires these routines to have SIFS be optional.
Notably though, the 11n version doesn't do any SIFS addition at the moment.
I'll go and tweak and verify all of the packet durations before I go and
flip that part on.
Tested:
* AR9330, STA mode
* AR9330, AP mode
* AR9380, STA mode
connectivity interact with the net80211 stack.
Historical background: originally wireless devices created an interface,
just like Ethernet devices do. Name of an interface matched the name of
the driver that created. Later, wlan(4) layer was introduced, and the
wlanX interfaces become the actual interface, leaving original ones as
"a parent interface" of wlanX. Kernelwise, the KPI between net80211 layer
and a driver became a mix of methods that pass a pointer to struct ifnet
as identifier and methods that pass pointer to struct ieee80211com. From
user point of view, the parent interface just hangs on in the ifconfig
list, and user can't do anything useful with it.
Now, the struct ifnet goes away. The struct ieee80211com is the only
KPI between a device driver and net80211. Details:
- The struct ieee80211com is embedded into drivers softc.
- Packets are sent via new ic_transmit method, which is very much like
the previous if_transmit.
- Bringing parent up/down is done via new ic_parent method, which notifies
driver about any changes: number of wlan(4) interfaces, number of them
in promisc or allmulti state.
- Device specific ioctls (if any) are received on new ic_ioctl method.
- Packets/errors accounting are done by the stack. In certain cases, when
driver experiences errors and can not attribute them to any specific
interface, driver updates ic_oerrors or ic_ierrors counters.
Details on interface configuration with new world order:
- A sequence of commands needed to bring up wireless DOESN"T change.
- /etc/rc.conf parameters DON'T change.
- List of devices that can be used to create wlan(4) interfaces is
now provided by net.wlan.devices sysctl.
Most drivers in this change were converted by me, except of wpi(4),
that was done by Andriy Voskoboinyk. Big thanks to Kevin Lo for testing
changes to at least 8 drivers. Thanks to pluknet@, Oliver Hartmann,
Olivier Cochard, gjb@, mmoll@, op@ and lev@, who also participated in
testing.
Reviewed by: adrian
Sponsored by: Netflix
Sponsored by: Nginx, Inc.
* 286410
* 286413
* 286416
The initial commit broke a variety of debug and features that aren't
in the GENERIC kernels but are enabled in other platforms.
with the net80211 stack.
Historical background: originally wireless devices created an interface,
just like Ethernet devices do. Name of an interface matched the name of
the driver that created. Later, wlan(4) layer was introduced, and the
wlanX interfaces become the actual interface, leaving original ones as
"a parent interface" of wlanX. Kernelwise, the KPI between net80211 layer
and a driver became a mix of methods that pass a pointer to struct ifnet
as identifier and methods that pass pointer to struct ieee80211com. From
user point of view, the parent interface just hangs on in the ifconfig
list, and user can't do anything useful with it.
Now, the struct ifnet goes away. The struct ieee80211com is the only
KPI between a device driver and net80211. Details:
- The struct ieee80211com is embedded into drivers softc.
- Packets are sent via new ic_transmit method, which is very much like
the previous if_transmit.
- Bringing parent up/down is done via new ic_parent method, which notifies
driver about any changes: number of wlan(4) interfaces, number of them
in promisc or allmulti state.
- Device specific ioctls (if any) are received on new ic_ioctl method.
- Packets/errors accounting are done by the stack. In certain cases, when
driver experiences errors and can not attribute them to any specific
interface, driver updates ic_oerrors or ic_ierrors counters.
Details on interface configuration with new world order:
- A sequence of commands needed to bring up wireless DOESN"T change.
- /etc/rc.conf parameters DON'T change.
- List of devices that can be used to create wlan(4) interfaces is
now provided by net.wlan.devices sysctl.
Most drivers in this change were converted by me, except of wpi(4),
that was done by Andriy Voskoboinyk. Big thanks to Kevin Lo for testing
changes to at least 8 drivers. Thanks to Olivier Cochard, gjb@, mmoll@,
op@ and lev@, who also participated in testing. Details here:
https://wiki.freebsd.org/projects/ifnet/net80211
Still, drivers: ndis, wtap, mwl, ipw, bwn, wi, upgt, uath were not
tested. Changes to mwl, ipw, bwn, wi, upgt are trivial and chances
of problems are low. The wtap wasn't compilable even before this change.
But the ndis driver is complex, and it is likely to be broken with this
commit. Help with testing and debugging it is appreciated.
Differential Revision: D2655, D2740
Sponsored by: Nginx, Inc.
Sponsored by: Netflix
doesn't get truncated to 32 bits.
Without this, 3x3 NICs transmitting at an MCS rate whose rix (rate
index) in the rate table is > 31 end up returning errors, as the
sample rate code doesn't think the rate is set in the rate table.
Tested:
* AR9380, STA, speaking 3x3 to an AP
to this event, adding if_var.h to files that do need it. Also, include
all includes that now are included due to implicit pollution via if_var.h
Sponsored by: Netflix
Sponsored by: Nginx, Inc.
routine.
There were still corner cases where the EWMA update stats are being
called on a rix which didn't have an intermediary stats update; thus
no packets were counted against it. Sigh.
This should fix the crashes I've been seeing on recent -HEAD.
rate.
This fixes two things:
* The intermediary rates now also have their EWMA values changed;
* The existing code was using the wrong value for longtries - so the
EWMA stats were only adjusted for the first rate and not subsequent
rates in a MRR setup.
TODO:
* Merge the EWMA updates into update_stats() now..
in some very degenerate conditions.
However, until ath_rate_form_aggr() is taught to not form aggregates
if ANY selected rate is non-MCS, this can't yet be enabled.
So, just add a comment.
* Don't treat high percentage failures as "sucessive failures" - high
MCS rates are very picky and will quite happily "fade" from low
to high failure % and back again within a few seconds. If they really
don't work, the aggregate will just plain fail.
* Only sample MCS rates +/- 3 from the current MCS. Sample will back off
quite quickly, so there's no need to sample _all_ MCS rates between
a high MCS rate and MCS0; there may be a lot of them.
* Modify the smoothing rate to be 75% rather than 95% - it's more adaptive
but it comes with a cost of being slightly less stable at times.
A per-node, hysterisis behaviour would be nicer.
This is required to support > MCS15 as more than 32 bit rate entries are
suddenly available.
This is quite messy - instead of doing typecasts at each mask operation,
this should be migrated to use a macro and have that do the typecast.
enabled.
The legacy (pre-802.11n) hardware doesn't support this - although
the AR5212 era hardware supports MRR, it doesn't have all the bits
needed to support MRR + RTS/CTS. The AR5416 and later support
a packet duration and RTS/CTS flags per rate scenario, so we should
support it.
Tested:
* AR9280, STA
PR: kern/170302
For now, the only module implement is 'sample', and that's only partially
implemented. The main issue here with reusing this structure in userland
is that it uses 'rix' everywhere, which requires the userland code to
have access to the current HAL rate table.
For now, this is a very large work in progress.
Specific details:
* The rate control information is per-node at the moment and wrapped
in a TLV, to ease parsing and backwards compatibility.
* .. but so I can be slack for now, the userland statistics are just
a copy of the kernel-land sample node state.
* However, for now use a temporary copy and change the rix entries
to dot11rate entries to make it slightly easier to eyeball.
Problems:
* The actual rate information table is unfortunately indexed by rix
and it doesn't contain a rate code. So the userland side of this
currently has no way to extract out a mapping.
TODO:
* Add a TLV payload to dump out the rate control table mapping so
'rix' can be turned into a dot11 / MCS rate.
* .. then remove the temporary copy.
the assumption that ath_softc doesn't change size based on build time
configuration.
I picked up on this because suddenly radar stuff didn't work; and
although the ath_dfs code was setting sc_dodfs=1, the main ath driver
saw sc_dodfs=0.
So for now, include opt_ath.h in driver source files. This seems like
the sane thing to do anyway.
I'll have to do a pass over the code at some later stage and turn
the radiotap TX/RX structs into malloc'ed memory, rather than in-line
inside of ath_softc. I'd rather like to keep ath_softc the same
layout regardless of configuration parameters.
Pointy hat to: adrian
been bait-and-switched from the rate control code.
This will avoid the panic that I saw and will avoid sending invalid rates
(eg 11a/11g OFDM rates when in 11b, on 11b-only NICs (AR5211)) where the
rate table is not "big".
It also will point out situations where this occurs for the 11n NICs
which will have sufficiently large rate tables that "invalid rix" doesn't
occur.
I'll try to follow this up with a commit that adds a current operating mode
check. The "rix" is only relevant to the current operating mode and rate
table.
PR: kern/165475
for Atheros AR5416 and later wireless devices.
This is a very large commit - the complete history can be
found in the user/adrian/if_ath_tx branch.
Legacy (ie, pre-AR5416) devices also use the per-software
TXQ support and (in theory) can support non-aggregation
ADDBA sessions. However, the net80211 stack doesn't currently
support this.
In summary:
TX path:
* queued frames normally go onto a per-TID, per-node queue
* some special frames (eg ADDBA control frames) are thrown
directly onto the relevant hardware queue so they can
go out before any software queued frames are queued.
* Add methods to create, suspend, resume and tear down an
aggregation session.
* Add in software retransmission of both normal and aggregate
frames.
* Add in completion handling of aggregate frames, including
parsing the block ack bitmap provided by the hardware.
* Write an aggregation function which can assemble frames into
an aggregate based on the selected rate control and channel
configuration.
* The per-TID queues are locked based on their target hardware
TX queue. This matches what ath9k/atheros does, and thus
simplified porting over some of the aggregation logic.
* When doing TX aggregation, stick the sequence number allocation
in the TX path rather than net80211 TX path, and protect it
by the TXQ lock.
Rate control:
* Delay rate control selection until the frame is about to
be queued to the hardware, so retried frames can have their
rate control choices changed. Frames with a static rate
control selection have that applied before each TX, just
to simplify the TX path (ie, not have "static" and "dynamic"
rate control special cased.)
* Teach ath_rate_sample about aggregates - both completion and
errors.
* Add an EWMA for tracking what the current "good" MCS rate is
based on failure rates.
Misc:
* Introduce a bunch of dirty hacks and workarounds so TID mapping
and net80211 frame inspection can be kept out of the net80211
layer. Because of the way this code works (and it's from Atheros
and Linux ath9k), there is a consistent, 1:1 mapping between
TID and AC. So we need to ensure that frames going to a specific
TID will _always_ end up on the right AC, and vice versa, or the
completion/locking will simply get very confused. I plan on
addressing this mess in the future.
Known issues:
* There is no BAR frame transmission just yet. A whole lot of
tidying up needs to occur before BAR frame TX can occur in the
"correct" place - ie, once the TID TX queue has been drained.
* Interface reset/purge/etc results in frames in the TX and RX
queues being removed. This creates holes in the sequence numbers
being assigned and the TX/RX AMPDU code (on either side) just
hangs.
* There's no filtered frame support at the present moment, so
stations going into power saving mode will simply have a number
of frames dropped - likely resulting in a traffic "hang".
* Raw frame TX is going to just not function with 11n aggregation.
Likely this needs to be modified to always override the sequence
number if the frame is going into an aggregation session.
However, general raw frame injection currently doesn't work in
general in net80211, so let's just ignore this for now until
this is sorted out.
* HT protection is just not implemented and won't be until the above
is sorted out. In addition, the AR5416 has issues RTS protecting
large aggregates (anything >8k), so the work around needs to be
ported and tested. Thus, this will be put on hold until the above
work is complete.
* The rate control module 'sample' is the only currently supported
module; onoe/amrr haven't been tested and have likely bit rotted
a little. I'll follow up with some commits to make them work again
for non-11n rates, but they won't be updated to handle 11n and
aggregation. If someone wishes to do so then they're welcome to
send along patches.
* .. and "sample" doesn't really do a good job of 11n TX. Specifically,
the metrics used (packet TX time and failure/success rates) isn't as
useful for 11n. It's likely that it should be extended to take into
account the aggregate throughput possible and then choose a rate
which maximises that. Ie, it may be acceptable for a higher MCS rate
with a higher failure to be used if it gives a more acceptable
throughput/latency then a lower MCS rate @ a lower error rate.
Again, patches will be gratefully accepted.
Because of this, ATH_ENABLE_11N is still not enabled by default.
Sponsored by: Hobnob, Inc.
Obtained from: Linux, Atheros
* 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.
Some files keep the SUN4V tags as a code reference, for the future,
if any rewamped sun4v support wants to be added again.
Reviewed by: marius
Tested by: sbruno
Approved by: re
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.
* 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.
determining whether to use MRR or not.
It uses the 11g protection mode when calculating 11n related stuff, rather
than checking the 11n protection mode.
Furthermore, the 11n chipsets can quite happily handle multi-rate retry w/
protection; the TX path and rate control modules need to be taught about
that.
* add dot11rate_label() which returns Mb or MCS based on legacy or HT
* use it everywhere dot11rate() is used
* in the "current selection" part at the top of the debugging output,
otuput what the rate itself is rather than the rix. The rate index
(rix) has very little meaning to normal humans who don't know how
to find the PHY settings for each of the chipsets; pointing out the
rix rate and type is likely more useful.
packet duration for the ath_rate_sample module.
This doesn't affect the packet TX at all; only how much time the
sample rate module attributes to a completed TX.
This doesn't yet take into account HT40 packet durations as the node info
(needed to know if it's a HT20 or HT40 node) isn't available everywhere
it needs to be.
This is just the bare minimum needed to teach ath_rate_sample to try
and handle MCS rates. It doesn't at all attempt to find the best
rate by any means - it doesn't know anything about the MCS rate
relations, TX aggregation or any of the much sexier 11n stuff
that's out there.
It's just enough to transmit 11n frames and handle TX completion.
It shouldn't affect legacy (11abg) behaviour.
Obtained from: rpaulo@
This removes the chipset-dependent TX DMA completion descriptor groveling.
It should now be (more) portable to other, later atheros chipsets when the
time comes.
module; the ath module now brings in the hal support. Kernel
config files are almost backwards compatible; supplying
device ath_hal
gives you the same chip support that the binary hal did but you
must also include
options AH_SUPPORT_AR5416
to enable the extended format descriptors used by 11n parts.
It is now possible to control the chip support included in a
build by specifying exactly which chips are to be supported
in the config file; consult ath_hal(4) for information.
