ath9k: add option to reset the wifi chip via debugfs

Sometimes, in yet unknown cases the wifi chip stops working. To allow a
watchdog in userspace to easily and quickly reset the wifi chip, add the

ath9k: add option to reset the wifi chip via debugfs

Sometimes, in yet unknown cases the wifi chip stops working. To allow a
watchdog in userspace to easily and quickly reset the wifi chip, add the
according functionality to userspace. A reset can then be triggered
via:

$ echo 1 > /sys/kernel/debug/ieee80211/phy0/ath9k/reset

The number of user resets can further be tracked in the row "User reset"
in the same file.

So far people usually used "iw scan" to fix ath9k chip hangs from
userspace. Which triggers the ath9k_queue_reset(), too. The reset file
however has the advantage of less overhead, which makes debugging bugs
within ath9k_queue_reset() easier.

Signed-off-by: Linus Lüssing <ll@simonwunderlich.de>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Link: https://lore.kernel.org/r/20210914192515.9273-2-linus.luessing@c0d3.blue

show more ...

ath9k: Switch to mac80211 TXQ scheduling and airtime APIs

This moves the ath9k driver to use the mac80211 TXQ scheduling and
airtime accounting APIs, removing the corresponding state tracking
inside

ath9k: Switch to mac80211 TXQ scheduling and airtime APIs

This moves the ath9k driver to use the mac80211 TXQ scheduling and
airtime accounting APIs, removing the corresponding state tracking
inside the driver.

Signed-off-by: Toke Høiland-Jørgensen <toke@toke.dk>
[rmanohar@codeaurora.org: fixed checkpatch error and warnings]
Signed-off-by: Rajkumar Manoharan <rmanohar@codeaurora.org>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>

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ath9k: fix RX_STAT_INC() etc macros

A couple of macros that deal with statistics in ath9k rely on the
declaration of the 'sc' variable, which they dereference.

However, when the statistics are disa

ath9k: fix RX_STAT_INC() etc macros

A couple of macros that deal with statistics in ath9k rely on the
declaration of the 'sc' variable, which they dereference.

However, when the statistics are disabled, the new instance in
ath_cmn_process_fft() causes a warning for an unused variable:

drivers/net/wireless/ath/ath9k/common-spectral.c: In function 'ath_cmn_process_fft':
drivers/net/wireless/ath/ath9k/common-spectral.c:474:20: error: unused variable 'sc' [-Werror=unused-variable]

It's better if those macros only operate on their arguments instead of
known variable names, and adding a cast to (void) kills off that warning.

Fixes: 03224678c013 ("ath9k: add counters for good and errorneous FFT/spectral frames")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>

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ath9k: Introduce airtime fairness scheduling between stations

This reworks the ath9k driver to schedule transmissions to connected
stations in a way that enforces airtime fairness between them. It
a

ath9k: Introduce airtime fairness scheduling between stations

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>

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ath9k: Switch to using mac80211 intermediate software queues.

This switches ath9k over to using the mac80211 intermediate software
queueing mechanism for data packets. It removes the queueing inside

ath9k: Switch to using mac80211 intermediate software queues.

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>

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ath9k: make DMA stop related messages debug-only

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, th

ath9k: make DMA stop related messages debug-only

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>

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ath: use seq_file api for ath9k debugfs files

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_o

ath: use seq_file api for ath9k debugfs files

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>

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ath9k: restart hardware after noise floor calibration failure

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 re

ath9k: restart hardware after noise floor calibration failure

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>

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ath9k & ath9k_htc: move ath_rx_stats to cmn

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@tuxd

ath9k & ath9k_htc: move ath_rx_stats to cmn

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>

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ath9k: Remove ath9k rate control

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

ath9k: Remove ath9k rate control

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>

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ath9k: Process GTT interrupts

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 regis

ath9k: Process GTT interrupts

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>

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ath9k: Add a debugfs file "node_recv"

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 <linvill

ath9k: Add a debugfs file "node_recv"

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>

show more ...

ath9k: move ath9k_debug_sync_cause out of ath9k_hw

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. Linvi

ath9k: move ath9k_debug_sync_cause out of ath9k_hw

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>

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ath9k: Cleanup spectral scan code

* 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. Linv

ath9k: Cleanup spectral scan code

* 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>

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ath9k: replace snprintf() with scnprintf()

Whenever the return value of snprintf() is used to calculate
remaining buffer-space, we wanted to use sncprintf() instead.

Indentation is adapted where po

ath9k: replace snprintf() with scnprintf()

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>

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ath9k: remove ath9k_sta_remove_debugfs

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 <nb

ath9k: remove ath9k_sta_remove_debugfs

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>

show more ...

ath9k: Add statistics for antenna diversity

Signed-off-by: Sujith Manoharan <c_manoha@qca.qualcomm.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

ath9k: Do a quick scan only when scan_not_start is true

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 <linvi

ath9k: Do a quick scan only when scan_not_start is true

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>

show more ...

ath9k: Remove unused structure ath_dbg_bb_mac_samp

Signed-off-by: Sujith Manoharan <c_manoha@qca.qualcomm.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

ath9k: Remove MAC_DEBUG

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 p

ath9k: Remove MAC_DEBUG

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>

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ath9k: Fix crash on module unload

Make sure that any open relayfs files are closed before
unregistering with mac80211, otherwise this crash is seen:

[ 1331.097846] BUG: unable to handle kernel pagi

ath9k: Fix crash on module unload

Make sure that any open relayfs files are closed before
unregistering with mac80211, otherwise this crash is seen:

[ 1331.097846] BUG: unable to handle kernel paging request at 6b6b6b8b
[ 1331.098170] IP: [<c063d0d6>] debugfs_remove+0x26/0x80
[ 1331.098170] *pdpt = 000000002f9aa001 *pde = 0000000000000000
[ 1331.098170] Oops: 0000 [#1] PREEMPT SMP
[ 1331.098170] Modules linked in: iptable_raw xt_CT nf_conntrack_ipv4 nf_defrag]
[ 1331.098170] Pid: 4794, comm: rmmod Tainted: G WC 3.9.1+ #5 To Be Fi.
[ 1331.098170] EIP: 0060:[<c063d0d6>] EFLAGS: 00010202 CPU: 0
[ 1331.098170] EIP is at debugfs_remove+0x26/0x80
[ 1331.098170] EAX: f2f3acd0 EBX: f2f3acd0 ECX: 00000006 EDX: f8622348
[ 1331.098170] ESI: 6b6b6b6b EDI: 00000001 EBP: ee251e14 ESP: ee251e0c
[ 1331.098170] DS: 007b ES: 007b FS: 00d8 GS: 00e0 SS: 0068
[ 1331.098170] CR0: 8005003b CR2: 6b6b6b8b CR3: 2e7b7000 CR4: 000007e0
[ 1331.098170] DR0: 00000000 DR1: 00000000 DR2: 00000000 DR3: 00000000
[ 1331.098170] DR6: ffff0ff0 DR7: 00000400
[ 1331.098170] Process rmmod (pid: 4794, ti=ee250000 task=efaa2560 task.ti=ee25)
[ 1331.098170] Stack:
[ 1331.098170] f241e170 0000000a ee251e1c f861394d ee251e28 c04e3088 f241e170 4
[ 1331.098170] c04e30fe f45482b0 ee251e54 c04e3187 f25e86b0 ee251e54 f8618748 0
[ 1331.098170] 0000000a 00000001 ee251e68 f860065b f2509e20 f25085a0 f5b6e8a4 8
[ 1331.098170] Call Trace:
[ 1331.098170] [<f861394d>] remove_buf_file_handler+0xd/0x20 [ath9k]
[ 1331.098170] [<c04e3088>] relay_remove_buf+0x18/0x30
[ 1331.098170] [<c04e30fe>] relay_close_buf+0x2e/0x40
[ 1331.098170] [<c04e3187>] relay_close+0x77/0xf0
[ 1331.098170] [<f8618748>] ? dpd_exit+0x38/0x40 [ath9k]
[ 1331.098170] [<f860065b>] ath9k_deinit_softc+0x8b/0xa0 [ath9k]
[ 1331.098170] [<f86006b8>] ath9k_deinit_device+0x48/0x60 [ath9k]
[ 1331.098170] [<f86107f1>] ath_pci_remove+0x31/0x50 [ath9k]
[ 1331.098170] [<c06dbff8>] pci_device_remove+0x38/0xc0
[ 1331.098170] [<c079daa4>] __device_release_driver+0x64/0xc0
[ 1331.098170] [<c079db97>] driver_detach+0x97/0xa0
[ 1331.098170] [<c079cacc>] bus_remove_driver+0x6c/0xe0
[ 1331.098170] [<c079c197>] ? bus_put+0x17/0x20
[ 1331.098170] [<c079cae3>] ? bus_remove_driver+0x83/0xe0
[ 1331.098170] [<c079e709>] driver_unregister+0x49/0x80
[ 1331.098170] [<c06dc138>] pci_unregister_driver+0x18/0x80
[ 1331.098170] [<f8610602>] ath_pci_exit+0x12/0x20 [ath9k]
[ 1331.098170] [<f8619ce0>] ath9k_exit+0x17/0x337 [ath9k]
[ 1331.098170] [<c09e537d>] ? mutex_unlock+0xd/0x10
[ 1331.098170] [<c04bd36c>] sys_delete_module+0x17c/0x250
[ 1331.098170] [<c0540dc4>] ? do_munmap+0x244/0x2d0
[ 1331.098170] [<c0540e96>] ? vm_munmap+0x46/0x60
[ 1331.098170] [<c09e8dc4>] ? restore_all+0xf/0xf
[ 1331.098170] [<c09ebf50>] ? __do_page_fault+0x4c0/0x4c0
[ 1331.098170] [<c04b18e4>] ? trace_hardirqs_on_caller+0xf4/0x180
[ 1331.098170] [<c09ef28d>] sysenter_do_call+0x12/0x38
[ 1331.098170] Code: 90 8d 74 26 00 55 89 e5 83 ec 08 89 1c 24 89 74 24 04 3e 82
[ 1331.098170] EIP: [<c063d0d6>] debugfs_remove+0x26/0x80 SS:ESP 0068:ee251e0c
[ 1331.098170] CR2: 000000006b6b6b8b
[ 1331.727971] ---[ end trace b5bb9f2066cef7f9 ]---

Cc: <stable@vger.kernel.org>
Acked-by: Simon Wunderlich <siwu@hrz.tu-chemnitz.de>
Tested-by: Ben Greear <greearb@candelatech.com>
Signed-off-by: Sujith Manoharan <c_manoha@qca.qualcomm.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

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ath9k: Report txerr-filtered errors in debugfs.

Signed-off-by: Ben Greear <greearb@candelatech.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

ath9k: drop spectral packets after processing them

Spectral packets are "bogus" packets and should not be further evaluated
by the RX path.

Statistics are added to keep track of these packets.

Sig

ath9k: drop spectral packets after processing them

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>

show more ...

ath9k: add a better fix for the rx tasklet vs rx flush race

Ensure that the rx tasklet is no longer running when entering the reset path.
Also remove the distinction between flush and no-flush frame

ath9k: add a better fix for the rx tasklet vs rx flush race

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>

show more ...

ath9k: add spectral scan feature

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 contr

ath9k: add spectral scan feature

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>

show more ...