This reworks the ath9k driver to schedule transmissions to connected
stations in a way that enforces airtime fairness between them. It
accomplishes this by measuring the time spent transmitting to or
receiving from a station at TX and RX completion, and accounting this to
a per-station, per-QoS level airtime deficit. Then, an FQ-CoDel based
deficit scheduler is employed at packet dequeue time, to control which
station gets the next transmission opportunity.
Airtime fairness can significantly improve the efficiency of the network
when station rates vary. The following throughput values are from a
simple three-station test scenario, where two stations operate at the
highest HT20 rate, and one station at the lowest, and the scheduler is
employed at the access point:
Before / After
Fast station 1: 19.17 / 25.09 Mbps
Fast station 2: 19.83 / 25.21 Mbps
Slow station: 2.58 / 1.77 Mbps
Total: 41.58 / 52.07 Mbps
The benefit of airtime fairness goes up the more stations are present.
In a 30-station test with one station artificially limited to 1 Mbps,
we have seen aggregate throughput go from 2.14 to 17.76 Mbps.
Signed-off-by: Toke Høiland-Jørgensen <toke@toke.dk>
Signed-off-by: Kalle Valo <kvalo@qca.qualcomm.com>
This switches ath9k over to using the mac80211 intermediate software
queueing mechanism for data packets. It removes the queueing inside the
driver, except for the retry queue, and instead pulls from mac80211 when
a packet is needed. The retry queue is used to store a packet that was
pulled but can't be sent immediately.
The old code path in ath_tx_start that would queue packets has been
removed completely, as has the qlen limit tunables (since there's no
longer a queue in the driver to limit).
The mac80211 intermediate software queues offer significant latency
reductions, and this patch allows ath9k to realise them. The exact gains
from this varies with the test scenario, but in an access point scenario
we have seen latency reductions ranging from 1/3 to as much as an order
of magnitude. We also achieve slightly better aggregation.
Median latency (ping) figures with this patch applied at the access point,
with two high-rate stations and one low-rate station (HT20 5Ghz), running
a Flent rtt_fair_var_up test with one TCP flow and one ping flow going to
each station:
Fast station Slow station
Default pfifo_fast qdisc: 430.4 ms 638.7 ms
fq_codel qdisc on iface: 35.5 ms 211.8 ms
This patch set: 22.4 ms 38.2 ms
Median aggregation sizes over the same test:
Default pfifo_fast qdisc: 9.5 pkts 1.9 pkts
fq_codel qdisc on iface: 11.2 pkts 1.9 pkts
This patch set: 13.9 pkts 1.9 pkts
This patch is based on Tim's original patch set, but reworked quite
thoroughly.
Cc: Tim Shepard <shep@alum.mit.edu>
Cc: Felix Fietkau <nbd@nbd.name>
Signed-off-by: Toke Høiland-Jørgensen <toke@toke.dk>
Signed-off-by: Kalle Valo <kvalo@qca.qualcomm.com>
A long time ago, ath9k had issues during reset where the DMA engine
would stay active and could potentially corrupt memory.
To debug those issues, the driver would print warnings whenever they
occur.
Nowadays, these issues are gone and the primary cause of these messages
is if the MAC is stuck during reset or busy processing a long
transmission. This is fairly harmless, yet these messages continue to
worry users.
To reduce the number of bogus bug reports, turn these messages into
debug messages and count their occurence in the "reset" debugfs file.
Signed-off-by: Felix Fietkau <nbd@openwrt.org>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Here's the set of driver core patches for 3.19-rc1.
They are dominated by the removal of the .owner field in platform
drivers. They touch a lot of files, but they are "simple" changes, just
removing a line in a structure.
Other than that, a few minor driver core and debugfs changes. There are
some ath9k patches coming in through this tree that have been acked by
the wireless maintainers as they relied on the debugfs changes.
Everything has been in linux-next for a while.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'driver-core-3.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core
Pull driver core update from Greg KH:
"Here's the set of driver core patches for 3.19-rc1.
They are dominated by the removal of the .owner field in platform
drivers. They touch a lot of files, but they are "simple" changes,
just removing a line in a structure.
Other than that, a few minor driver core and debugfs changes. There
are some ath9k patches coming in through this tree that have been
acked by the wireless maintainers as they relied on the debugfs
changes.
Everything has been in linux-next for a while"
* tag 'driver-core-3.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (324 commits)
Revert "ath: ath9k: use debugfs_create_devm_seqfile() helper for seq_file entries"
fs: debugfs: add forward declaration for struct device type
firmware class: Deletion of an unnecessary check before the function call "vunmap"
firmware loader: fix hung task warning dump
devcoredump: provide a one-way disable function
device: Add dev_<level>_once variants
ath: ath9k: use debugfs_create_devm_seqfile() helper for seq_file entries
ath: use seq_file api for ath9k debugfs files
debugfs: add helper function to create device related seq_file
drivers/base: cacheinfo: remove noisy error boot message
Revert "core: platform: add warning if driver has no owner"
drivers: base: support cpu cache information interface to userspace via sysfs
drivers: base: add cpu_device_create to support per-cpu devices
topology: replace custom attribute macros with standard DEVICE_ATTR*
cpumask: factor out show_cpumap into separate helper function
driver core: Fix unbalanced device reference in drivers_probe
driver core: fix race with userland in device_add()
sysfs/kernfs: make read requests on pre-alloc files use the buffer.
sysfs/kernfs: allow attributes to request write buffer be pre-allocated.
fs: sysfs: return EGBIG on write if offset is larger than file size
...
The debugfs files that are defined in debug.c which are read-only
and using a simple_open as .open file operation have been modified
to use the single_open seq_file API. This simplifies the read
functions defining the file contents.
Signed-off-by: Arend van Spriel <arend@broadcom.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When NF calibration fails, the radio often becomes deaf. The usual
hardware hang checks do not detect this, so it's better to issue a reset
when that happens.
Signed-off-by: Felix Fietkau <nbd@openwrt.org>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
and use it. This move need changes in both drivers.
Signed-off-by: Oleksij Rempel <linux@rempel-privat.de>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
There is no benefit in retaining the legacy rate control module
in the driver codebase.
It is known to be buggy and has less than optimal performance
in real-world environments compared with minstrel. The only
reason that it was kept when we made the switch to minstrel
as default was that it showed higher throughput numbers in a
clean/ideal environment.
This is no longer the case and minstrel can push ath9k to
the same throughput levels. In TCP, with 3-stream cards, more than
295 Mbps can be obtained in open air, with 2-stream cards,
210 Mbps is easily reached. To test performance issues,
instead of using a broken rate control module, it is better
to use the fixed-rate interface provided by mac80211 anyway.
The ath9k RC has not received any bug fixes in years and is
just bit-rotting away - this patch removes it.
Signed-off-by: Sujith Manoharan <c_manoha@qca.qualcomm.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Global Transmission Timeout interrupts are generated by
the HW when transmission of a frame fails - this is done
based on the threshold programmed in the AR_GTXTO register.
Currently, even though the interrupt is enabled for all chips,
it is not handled in the driver. This patch handles GTT events
for AR9003 and above chips, checking if the MAC/BB has hung
after successive GTT interrupts crosses a threshold (5).
This can be enabled for the older chips in the AR9002 family once
appropriate HW hang checks are implemented for them.
Signed-off-by: Sujith Manoharan <c_manoha@qca.qualcomm.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
This would be useful when debugging RX performance issues.
Signed-off-by: Sujith Manoharan <c_manoha@qca.qualcomm.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
ath9k_hw should not depend on any ath9k data structures like ath_softc
Signed-off-by: Felix Fietkau <nbd@openwrt.org>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
* Move definitions to spectral.h
* Move processing/debug code to spectral.c
Signed-off-by: Sujith Manoharan <c_manoha@qca.qualcomm.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Whenever the return value of snprintf() is used to calculate
remaining buffer-space, we wanted to use sncprintf() instead.
Indentation is adapted where possible. Some lines exceed the
line width limit, either they did it already before, or
since they can not be broken reasonably well.
Signed-off-by: Zefir Kurtisi <zefir.kurtisi@neratec.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
mac80211 uses debugfs_remove_recursive, so there's no need for the
driver to do an explicit cleanup of its sta debugfs entry.
Signed-off-by: Felix Fietkau <nbd@openwrt.org>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Right now, it is being done for all cases.
Signed-off-by: Sujith Manoharan <c_manoha@qca.qualcomm.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
This option has not been enabled by default in any
distribution, has never been enabled in OpenWrt and no developer
has asked for this information in a bug report.
Dumping pages of random values doesn't help debugging,
remove this option (along with the vmalloc() abuse).
Signed-off-by: Sujith Manoharan <c_manoha@qca.qualcomm.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Spectral packets are "bogus" packets and should not be further evaluated
by the RX path.
Statistics are added to keep track of these packets.
Signed-off-by: Simon Wunderlich <siwu@hrz.tu-chemnitz.de>
Signed-off-by: Mathias Kretschmer <mathias.kretschmer@fokus.fraunhofer.de>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Ensure that the rx tasklet is no longer running when entering the reset path.
Also remove the distinction between flush and no-flush frame processing.
If a frame has been received and ACKed by the hardware, the stack needs to see
it, so that the BA receive window does not go out of sync.
Cc: stable@vger.kernel.org
Signed-off-by: Felix Fietkau <nbd@openwrt.org>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Adds the spectral scan feature for ath9k. AR92xx and AR93xx chips
are supported for now. The spectral scan is triggered by configuring
a mode through a debugfs control file. Samples can be gathered via
another relay debugfs file.
Essentially, to try it out:
echo chanscan > /sys/kernel/debug/ieee80211/phy0/ath9k/spectral_scan_ctl
iw dev wlan0 scan
cat /sys/kernel/debug/ieee80211/phy0/ath9k/spectral_scan0 > samples
echo disable > /sys/kernel/debug/ieee80211/phy0/ath9k/spectral_scan_ctl
This feature is still experimental.
The special "chanscan" mode is used to perform spectral scan while
mac80211 is scanning for channels. To allow this,
sw_scan_start/complete() ops have been added.
The patch contains code snippets and information from Zefir Kurtisi and
information provided by Adrian Chadd and Felix Fietkau.
Signed-off-by: Simon Wunderlich <siwu@hrz.tu-chemnitz.de>
Signed-off-by: Mathias Kretschmer <mathias.kretschmer@fokus.fraunhofer.de>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Commit "ath9k: Fix the 'xmit' debugfs file" changed the
the array size of ath_stats.txstats to IEEE80211_NUM_ACS,
which is wrong because the HW queue number is used to
update the statistics. Revert back to using ATH9K_NUM_TX_QUEUES.
Reported-by: Felix Fietkau <nbd@openwrt.org>
Signed-off-by: Sujith Manoharan <c_manoha@qca.qualcomm.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
The ethtool statistics are available only when
CONFIG_ATH9K_DEBUGFS is enabled, move these functions
to debug.c
Signed-off-by: Sujith Manoharan <c_manoha@qca.qualcomm.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
The 'xmit' debugfs file has become big and unwieldy, fix
multiple issues with its usage:
* Store TX counters/statistics only for the 4 Access Categories.
Use IEEE80211_NUM_ACS instead of ATH9K_NUM_TX_QUEUES.
* Move various utility macros to debug.h, they can be reused
elsewhere.
* Remove tx_complete_poll_work_seen.
* Remove code that accesses various internal queue-specific
variables without any locking whatsoever. HW/SW queue details
will be handled in a subsequent patch.
* Do not print internal values like txq_headidx and txq_headidx.
They were mostly unused anyway, considering code like:
PRX("txq_tailidx: ", txq_headidx);
* Handle 'txprocdesc' for EDMA too.
Signed-off-by: Sujith Manoharan <c_manoha@qca.qualcomm.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
This patch reverts the commit "ath9k_hw: Wait BT calibration to complete"
and bail out from MCI interrupt routine for chip reset. The above commit
stalls the WLAN TCP traffic while bringing up and down the BT interface
iteratively. Fixing this properly by queueing up chip reset and bailing
out properly from tasklet routine.
Signed-off-by: Rajkumar Manoharan <rmanohar@qca.qualcomm.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Whenever BT calibration requested, WLAN has to wait for the
calibration to be completed. But right now we defer the waiting
which might cause BT calibration to fail. Fix that.
Signed-off-by: Rajkumar Manoharan <rmanohar@qca.qualcomm.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Having generic hardware timer interrupt in debugfs
would come handy when we are debugging 3 WIRE
BTCOEX issues.
Signed-off-by: Mohammed Shafi Shajakhan <mohammed@qca.qualcomm.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Using work_pending() to defer certain operations when
a HW-reset work has been queued is racy since the check
would return false when the work item is actually in
execution. Use SC_OP_HW_RESET instead to fix this race.
Also, unify the reset debug statistics maintenance.
Signed-off-by: Rajkumar Manoharan <rmanohar@qca.qualcomm.com>
Signed-off-by: Sujith Manoharan <c_manoha@qca.qualcomm.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Report all defined sync_cause errors in debugfs
to aid with debugging.
Use a macro to print out the interrupts file contents
to decrease code duplication.
Signed-off-by: Ben Greear <greearb@candelatech.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
This adds counters in various places that can drop packets on
rx without otherwise incrementing a counter. It also counts
some non-error cases, such as becons and fragments received.
Should help with figuring out where packets are (and are not)
dropped.
Signed-off-by: Ben Greear <greearb@candelatech.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
This counts any failure during getting packets into
the DMA buffers, including out-of-memory, etc.
Signed-off-by: Ben Greear <greearb@candelatech.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
In the experiment with Azimuth ADEPT-n testbed where the APs transmit
power was reduced to 25% and the signal strength was futher attenuated
by 20dB and induced a path loss of ~7dB, the station was reporting
beacon losses and the following issue were observed.
* rx clear is stuck at low for more than 300ms
* dcu chain and complete state is stuck at one of the hang signature
This patch triggers the hang detection logic that recovers the chip
from any of the above conditions. As the issue was originally reported
in ChromeOs with AR9382 chips, this detection logic is enabled only for
AR9380/2 chips.
Cc: Paul Stewart <pstew@google.com>
Reported-by: Gary Morain <gmorain@google.com>
Signed-off-by: Rajkumar Manoharan <rmanohar@qca.qualcomm.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
The way this is implemented (simply storing the last value) is absolutely
worthless for debugging anything, and the same information is also available
through the MAC sample feature, so there's no point in keeping this around.
Signed-off-by: Felix Fietkau <nbd@openwrt.org>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
They're more expensive than some of the other debug options and only used
in very rare situations, so it sometimes makes sense to disable them while
leaving in debugfs support.
Signed-off-by: Felix Fietkau <nbd@openwrt.org>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
This initial DFS module provides basic functionality to deal
with radar pulses reported by the Atheros DFS HW pulse detector.
The reported data is evaluated and basic plausibility checks
are performed to filter false pulses. Passing radar pulses are
forwarded to pattern detectors which are not yet implemented.
(Some modifications to actually use ATH9K_DFS_DEBUGFS based on comments
from Julian Calaby <julian.calaby@gmail.com>. -- JWL)
Signed-off-by: Zefir Kurtisi <zefir.kurtisi@neratec.com>
Signed-off-by: Luis R. Rodriguez <mcgrof@qca.qualcomm.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Export how many times each of the reset triggers has fired through debugfs.
Signed-off-by: Felix Fietkau <nbd@openwrt.org>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
this represents the bitmap of block ACK received after the
successful transmission of an aggregate frame. also made few
changes to beautify the display
Signed-off-by: Mohammed Shafi Shajakhan <mohammed@qca.qualcomm.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
This patch keep track of number of samples that includes
DMA debugs registers, PCU observe, CR, channel noise,
cycle conters, noisefloor history buffer and last N number
of tx and rx descriptor status. These samples are grouped
in table manner which dumping in debgufs.
Debugfs file location:
<debugfs_mnt>/ieee80211/phy#/ath9k/samples
Signed-off-by: Rajkumar Manoharan <rmanohar@qca.qualcomm.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
This helped the developers to fix an issue of chip not entering network
sleep during idle state, previously this was only available as a debug
message
Signed-off-by: Mohammed Shafi Shajakhan <mshajakhan@atheros.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Export RSSI information from all the control and extension
channel chains to debugfs. Also add rx antenna information
to debugfs. This will be useful for debugging purpose.
Signed-off-by: Senthil Balasubramanian <senthilkumar@atheros.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
"ath9k: fix tx queue index confusion in debugfs code" changed the debug
function but not the stub.
Signed-off-by: Felix Fietkau <nbd@openwrt.org>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Toke Høiland-Jørgensen