The DMA latency issue is observed only in Intel pinetrail platforms
but in the driver we had a default PM-QOS value of 55. This caused
unnecessary power consumption and battery drain in other platforms.

Remove the pm-qos thing in the driver code and address the throughput
issue in Intel pinetrail platfroms in user space using any one of
the scripts in below links:

http://www.kernel.org/pub/linux/kernel/people/mcgrof/scripts/cpudmalatency.c
http://johannes.sipsolutions.net/files/netlatency.c.txt

More details can be found in the following bugzilla link:

https://bugzilla.kernel.org/show_bug.cgi?id=27532

This reverts the following commits:

	98c316e3
	4dc3530d
	10598c12Signed-off-by: NMohammed Shafi Shajakhan <mshajakhan@atheros.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

This patch reverts the following commit
ath9k: remove bfs_paprd_timestamp from struct ath_buf_state

Under high interference/noisy environment conditions where PAPRD frames
fails heavily introduces a possibility of double freeing skb's and causes
kernel panic after some time.This patch reverts back to the original approach
of using paprd_timestamp before freeing the PAPRD frame skb's

[  194.193705] Pid: 0, comm: swapper Tainted: G      D WC
2.6.35-22-generic #33-Ubuntu
[  194.193712] Call Trace:
[  194.193722]  [<c05c6468>] ? printk+0x2d/0x35
[  194.193732]  [<c05c63c3>] panic+0x5a/0xd2
[  194.193741]  [<c05ca3ed>] oops_end+0xcd/0xd0
[  194.193750]  [<c0105f74>] die+0x54/0x80
[  194.193758]  [<c05c9a16>] do_trap+0x96/0xc0
[  194.193837]  [<c0103fb0>] ? do_invalid_op+0x0/0xa0
[  194.193846]  [<c010403b>] do_invalid_op+0x8b/0xa0
[  194.193856]  [<c020bd4c>] ? kfree+0xec/0xf0
[  194.193866]  [<c012ce18>] ? default_spin_lock_flags+0x8/0x10
[  194.193877]  [<c01de47a>] ? free_one_page+0x12a/0x2d0
[  194.193888]  [<c01e04dc>] ? __free_pages+0x1c/0x40
[  194.193897]  [<c05c97a7>] error_code+0x73/0x78
[  194.193906]  [<c020bd4c>] ? kfree+0xec/0xf0
[  194.193915]  [<c04ecdd0>] ? skb_release_data+0x70/0xa0
[  194.193924]  [<c04ecdd0>] skb_release_data+0x70/0xa0
[  194.193933]  [<c04ec997>] __kfree_skb+0x17/0x90
[  194.193941]  [<c04eca31>] consume_skb+0x21/0x40
[  194.193964]  [<f85e0b70>] ieee80211_tx_status+0x760/0x860 [mac80211]
[  194.193979]  [<f85caddf>] ath_tx_complete_buf+0x1bf/0x2c0 [ath9k]
[  194.193988]  [<c05c8b9f>] ? _raw_spin_lock_irqsave+0x2f/0x50
[  194.193997]  [<c04ec40e>] ? skb_queue_tail+0x3e/0x50
[  194.194010]  [<f85cc803>] ath_tx_complete_aggr+0x823/0x940 [ath9k]
[  194.194021]  [<c0108a28>] ? sched_clock+0x8/0x10
[  194.194030]  [<c016bf14>] ? sched_clock_local+0xa4/0x180
[  194.194040]  [<c0139f57>] ? enqueue_sleeper+0x1e7/0x2b0
[  194.194051]  [<c013a194>] ? enqueue_entity+0x174/0x200
[  194.194064]  [<f85ce83d>] ath_tx_edma_tasklet+0x2bd/0x3b0 [ath9k]
[  194.194074]  [<c05c8b9f>] ? _raw_spin_lock_irqsave+0x2f/0x50
[  194.194088]  [<f85c7b9f>] ath9k_tasklet+0x9f/0x190 [ath9k]
[  194.194097]  [<c01505d7>] tasklet_action+0xa7/0xb0
[  194.194107]  [<c015127c>] __do_softirq+0x9c/0x1b0
[  194.194117]  [<c01a7f64>] ? irq_to_desc+0x14/0x20
[  194.194126]  [<c0124fc4>] ? ack_apic_level+0x64/0x1f0
[  194.194136]  [<c01513d5>] do_softirq+0x45/0x50
[  194.194145]  [<c0151545>] irq_exit+0x65/0x70
[  194.194153]  [<c05cf665>] do_IRQ+0x55/0xc0
[  194.194162]  [<c016a6c7>] ? hrtimer_start+0x27/0x30
[  194.194171]  [<c0103630>] common_interrupt+0x30/0x38
[  194.194181]  [<c012c21a>] ? native_safe_halt+0xa/0x10
[  194.194268]  [<c010a2f9>] default_idle+0x49/0xb0
[  194.194277]  [<c0101fcc>] cpu_idle+0x8c/0xd0
[  194.194286]  [<c05b2431>] rest_init+0x71/0x80
[  194.194295]  [<c081981a>] start_kernel+0x36e/0x374
[  194.194305]  [<c08199dd>] ? pass_all_bootoptions+0x0/0xa
[  194.194314]  [<c08190d7>] i386_start_kernel+0xd7/0xdf
[  194.194364] panic occurred, switching back to text console
Signed-off-by: NMohammed Shafi Shajakhan <mshajakhan@atheros.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

It looks like some hardware registers are left into undefined state
after suspend/resume. At minimum, this can cause odd issues related to
key cache and hardware trying to encrypt/decrypt frames unexpectedly.
This seems to happen even when there is no keys configured, i.e., hardware
can end up touching TX frames just based of invalid key cache context
even if the driver is not asking a specific entry to be used. In
addition, RX can likely be affected. This patch fixes this issue.
Signed-off-by: NJouni Malinen <Jouni.Malinen@Atheros.com>
Signed-off-by: NMohammed Shafi Shajakhan <mshajakhan@atheros.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

The recently added warning message on power change failure
is not needed on device removal.

ath: Failed to wakeup in 500us
------------[ cut here ]------------
WARNING: at drivers/net/wireless/ath/ath9k/hw.c:1618
ath9k_hw_setpower+0x61f/0x630 [ath9k_hw]()
Hardware name: 64756D6
Pid: 540, comm: kworker/u:3 Not tainted 2.6.37-rc6-wl #37
Call Trace:
 [<ffffffff810501aa>] warn_slowpath_common+0x7a/0xb0
 [<ffffffffa056e280>] ? ath9k_iowrite32+0x0/0x90 [ath9k]
 [<ffffffff810501f5>] warn_slowpath_null+0x15/0x20
 [<ffffffffa05226ef>] ath9k_hw_setpower+0x61f/0x630 [ath9k_hw]
 [<ffffffffa05700e5>] ath9k_ps_wakeup+0x85/0xd0 [ath9k]
 [<ffffffffa0570685>] ath9k_configure_filter+0x25/0x80 [ath9k]
 [<ffffffffa04dde43>] ieee80211_configure_filter+0x133/0x190 [mac80211]
 [<ffffffffa04ee502>] ieee80211_do_stop+0x132/0x540 [mac80211]
 [<ffffffff813466ff>] ? _raw_spin_unlock_bh+0x1f/0x30
 [<ffffffff812b6923>] ? dev_deactivate+0x1c3/0x1e0
 [<ffffffffa04ee925>] ieee80211_stop+0x15/0x20 [mac80211]
 [<ffffffff8129d1b6>] __dev_close+0x56/0x90
Signed-off-by: NRajkumar Manoharan <rmanoharan@atheros.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Restricting the chainmask to 1 for legacy mode disables useful features
such as MRC, and it reduces the available transmit power.
I can't think of a good reason to do this in legacy mode, so let's just
get rid of that code.
Signed-off-by: NFelix Fietkau <nbd@openwrt.org>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

To improve aggregation length, there should not be more than two fully formed
A-MPDU frames in the hardware queue. To ensure this, the code checks the tx
queue length before forming new A-MPDUs. This can reduce the throughput (or
maybe even starve out A-MPDU traffic) when too many non-aggregated frames are
in the queue.
Fix this by keeping track of pending A-MPDU frames (even when they're sent out
as single frames), but exclude rate control probing frames to improve
performance.
Signed-off-by: NFelix Fietkau <nbd@openwrt.org>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

This patch allows the pm-qos value to be user configurable by making it as
a module parameter.This will help our customers to configure the pm-qos
value according to the effect in throughput due to the DMA latency problem
which was observed in Intel Pinetrail platforms.
	The tested value of '55' will be filled as the default
pm-qos-value incase the user does not specifies pm-qos value as a
module parameter.
example usage: sudo modprobe ath9k pmqos=65

Cc: Senthilkumar Balasubramanian <Senthilkumar.Balasubramanian@Atheros.com>
Signed-off-by: NMohammed Shafi Shajakhan <mshajakhan@atheros.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

When ath_drain_all_txq fails to stop DMA, it issues a hw reset. This reset
happens at a very problematic point in time, when the hardware rx path has
not been stopped yet. This could lead to memory corruption, hardware hangs
or other issues.
To fix these issues, simply remove the reset entirely and check the tx DMA
stop status to prevent problems with fast channel changes.
Signed-off-by: NFelix Fietkau <nbd@openwrt.org>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

This feature is to mitigate the problem of certain 3
stream chips that exceed the PCIe power requirements.An EEPROM flag
controls which chips have APM enabled which is basically read from
miscellaneous configuration element of the EEPROM header.

This workaround will reduce power consumption by using 2 Tx chains for
Single and Double stream rates (5 GHz only).All self generated frames
(regardless of rate) are sent on 2 chains when this feature is
enabled(Chip Limitation).

Cc: Paul Shaw <paul.shaw@atheros.com>
Signed-off-by: NMohammed Shafi Shajakhan <mshajakhan@atheros.com>
Tested-by: NMohammed Shafi Shajakhan <mshajakhan@atheros.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

The ath9k driver uses a shared pm_qos_request_list structure for all
devices. This causes the following warning if more than one device is
present in the system:

WARNING: at kernel/pm_qos_params.c:234 ath9k_init_device+0x5e8/0x6b0()
pm_qos_add_request() called for already added request
Modules linked in:
Call Trace:
[<802b1cdc>] dump_stack+0x8/0x34
[<8007dd90>] warn_slowpath_common+0x78/0xa4
[<8007de44>] warn_slowpath_fmt+0x2c/0x38
[<801b0828>] ath9k_init_device+0x5e8/0x6b0
[<801bc508>] ath_pci_probe+0x2dc/0x39c
[<80176254>] pci_device_probe+0x64/0xa4
[<8019471c>] driver_probe_device+0xbc/0x188
[<80194854>] __driver_attach+0x6c/0xa4
[<80193e20>] bus_for_each_dev+0x60/0xb0
[<80193580>] bus_add_driver+0xcc/0x268
[<80194c08>] driver_register+0xe0/0x198
[<801764e0>] __pci_register_driver+0x50/0xe0
[<80365f48>] ath9k_init+0x3c/0x6c
[<8006050c>] do_one_initcall+0xfc/0x1d8
[<80355340>] kernel_init+0xd4/0x174
[<800639a4>] kernel_thread_helper+0x10/0x18

---[ end trace 5345fc6f870564a6 ]---

This patch fixes that warning by using a separate pm_qos_request_list
sructure for each device.
Signed-off-by: NGabor Juhos <juhosg@openwrt.org>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Since the pointers after the rates in the tx info cannot be used anymore
after frames have been queued, this area can be used to store information
that was previously stored in the ath_buf. With these changes, we can delay
the ath_buf assignment in the aggregation code until aggregates are formed.

That will not only make it possible to simplify DMA descriptor setup to
do less rewriting of uncached memory, but will also make it easier to
move aggregation out of the core of the ath9k tx path.
Signed-off-by: NFelix Fietkau <nbd@openwrt.org>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

- remove the BUF_HT flag, and instead check for IEEE80211_TX_CTL_AMPDU
  before calling ath_tx_send_ampdu.
- remove a few unused variables
- calculate frame length before adding the frame padding
- merge the misnamed ath_tx_start_dma function into ath_tx_start
- remove an unused argument for assign_aggr_tid_seqno
Signed-off-by: NFelix Fietkau <nbd@openwrt.org>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Merge initial processing for the CAB queue and regular tx.
Also move ath_tx_cabq() to beacon.c and make it static.
Signed-off-by: NFelix Fietkau <nbd@openwrt.org>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Signed-off-by: NFelix Fietkau <nbd@openwrt.org>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Signed-off-by: NFelix Fietkau <nbd@openwrt.org>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Signed-off-by: NFelix Fietkau <nbd@openwrt.org>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Signed-off-by: NFelix Fietkau <nbd@openwrt.org>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Signed-off-by: NFelix Fietkau <nbd@openwrt.org>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Signed-off-by: NFelix Fietkau <nbd@openwrt.org>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Signed-off-by: NFelix Fietkau <nbd@openwrt.org>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Signed-off-by: NFelix Fietkau <nbd@openwrt.org>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Signed-off-by: NFelix Fietkau <nbd@openwrt.org>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Signed-off-by: NFelix Fietkau <nbd@openwrt.org>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

There is a roundng error in delimiter padding computation
which causes severe throughput drop with some of AR9003.
signed-off-by: NFelix Fietkau <nbd@openwrt.org>
Signed-off-by: NVasanthakumar Thiagarajan <vasanth@atheros.com>
Cc:stable@kernel.org
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

The current ath9k tx queue handling code showed a few issues that could
lead to locking issues, tx stalls due to stopped queues, and maybe even
DMA issues.

The main source of these issues is that in some places the queue is
selected via skb queue mapping in places where this mapping may no
longer be valid. One such place is when data frames are transmitted via
the CAB queue (for powersave buffered frames). This is made even worse
by a lookup WMM AC values from the assigned tx queue (which is
undefined for the CAB queue).

This messed up the pending frame counting, which in turn caused issues
with queues getting stopped, but not woken again.

To fix these issues, this patch removes an unnecessary abstraction
separating a driver internal queue number from the skb queue number
(not to be confused with the hardware queue number).

It seems that this abstraction may have been necessary because of tx
queue preinitialization from the initvals. This patch avoids breakage
here by pushing the software <-> hardware queue mapping to the function
that assigns the tx queues and redefining the WMM AC definitions to
match the numbers used by mac80211 (also affects ath9k_htc).

To ensure consistency wrt. pending frame count tracking, these counters
are moved to the ath_txq struct, updated with the txq lock held, but
only where the tx queue selected by the skb queue map actually matches
the tx queue used by the driver for the frame.
Signed-off-by: NFelix Fietkau <nbd@openwrt.org>
Reported-by: NBjörn Smedman <bjorn.smedman@venatech.se>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

The PCU lock should be used to contend TX DMA as well,
this will be done next.

This is part of a series of patches which fix stopping
TX DMA completley when requested on the driver.
For more details about this issue refer to this thread:

http://marc.info/?l=linux-wireless&m=128629803703756&w=2Tested-by: NBen Greear <greearb@candelatech.com>
Cc: Kyungwan Nam <kyungwan.nam@atheros.com>
Cc: stable@kernel.org
Signed-off-by: NLuis R. Rodriguez <lrodriguez@atheros.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

The new PCU lock is better placed so we can just contend
against that when trying to reset hardware.

This is part of a series of patches which fix stopping
TX DMA completley when requested on the driver.
For more details about this issue refer to this thread:

http://marc.info/?l=linux-wireless&m=128629803703756&w=2Tested-by: NBen Greear <greearb@candelatech.com>
Cc: Kyungwan Nam <kyungwan.nam@atheros.com>
Cc: stable@kernel.org
Signed-off-by: NLuis R. Rodriguez <lrodriguez@atheros.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

ANI needs the RSSI average only in station mode, and only for tracking
the signal strength of beacons of the AP that it is connected to.
Adjust the code to track on the beacon RSSI, and store the average of that
in the ath_wiphy struct.
With these changes, we can get rid of this extra station lookup in the
rx path, which saves precious CPU cycles.
Signed-off-by: NFelix Fietkau <nbd@openwrt.org>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Throughput was severely affected in Intel Pinetrail platforms
because of a DMA problem in C3 state. This patch fixes this
issue.
Signed-off-by: NVivek Natarajan <vnatarajan@atheros.com>
CC: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

The real way to lock RX is to contend on the PCU
and reset, this will be fixed in the next patch but for
now just do the renames so that the next patch which changes
the locking order is crystal clear.

This is part of a series that will help resolve the bug:

https://bugzilla.kernel.org/show_bug.cgi?id=14624

For more details about this issue refer to:

http://marc.info/?l=linux-wireless&m=128629803703756&w=2

Cc: stable@kernel.org
Cc: Ben Greear <greearb@candelatech.com>
Cc: Kyungwan Nam <kyungwan.nam@atheros.com>
Signed-off-by: NLuis R. Rodriguez <lrodriguez@atheros.com>
Tested-by: NBen Greear <greearb@candelatech.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

The bf_dmacontext seems to be totally useless and duplicated
by bf_buf_addr.  Remove it entirely, use bf_buf_addr in its
place.
Signed-off-by: NBen Greear <greearb@candelatech.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Set the rate table in the rc module properly based on band and
HT capabilities instead, which was already partially done, but
not for every mode.
Signed-off-by: NFelix Fietkau <nbd@openwrt.org>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Results for the active channel are updated whenever a new survey dump
is requested, the old data is kept to allow multiple processes to
make their own channel utilization averages.
All other channels only contain the data for the last time that the
hardware was on the channel, i.e. the last scan result or other
off-channel activity.
Running a background scan does not clear the data for the active
channel.
Signed-off-by: NFelix Fietkau <nbd@openwrt.org>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

drv_config callback is called only after the ack for the nullframe
is received and so driver need not do anything special for this.

So remove NULLFUNC_COMPLETED, PS_ENABLED flags and bf_isnullfunc
flags from ath9k as mac80211 already handles them properly.
Signed-off-by: NSenthil Balasubramanian <senthilkumar@atheros.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

It is not used anywhere else and can be made static
Signed-off-by: NFelix Fietkau <nbd@openwrt.org>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

A new aggregation session start can be issued by mac80211, even when the
cleanup of the previous session has not completed yet. Since the data structure
for the session is not recreated, this could corrupt the block ack window
and lock up the aggregation session. Fix this by delaying the new session
until the old one has been cleaned up.
Signed-off-by: NFelix Fietkau <nbd@openwrt.org>
Cc: stable@kernel.org
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

There's no reason to keep pointers to pending tx buffers around, if they're
only used to keep track of which frames are still pending. Use a bitfield
instead.
Signed-off-by: NFelix Fietkau <nbd@openwrt.org>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

ath9k's entire logic with SC_OP_SCANNING is incorrect due to the
way mac80211 currently implements the scan complete callback and
we handle it in ath9k. This patch removes the flag completely in
preference for the SC_OP_OFFCHANNEL which is really what we wanted.

The scanning flag was used to ensure we reset ANI to the old values
when we go back to the home channel, but if we are offchannel we
use some defaults. The flag was also used to re-enable the TX monitor.

Without this patch we simply never re-enabled ANI and the TX monitor
after going offchannel. This means that after one background
scan we are prone to noise issues and if we had a TX hang we would
not recover. To get this to work properly we must enable ANI after
we have configured the beacon timers, otherwise hardware acts really
oddly.

This patch has stable fixes which apply down to [2.6.36+], there
*may* be a to fix this on older kernels but requires a bit of
work since this patch relies on the new mac80211 flag
IEEE80211_CONF_OFFCHANNEL which was introduced as of 2.6.36.

Cc: stable@kernel.org
Cc: Paul Stewart <pstew@google.com>
Cc: Amod Bodas <amod.bodas@atheros.com>
Signed-off-by: NLuis R. Rodriguez <lrodriguez@atheros.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

At the time the .add_interface driver op is called, the interface has not
been marked as running yet, so ieee80211_iterate_active_interfaces will
not pass it to the iterator function.
Because of this, the calculated BSSID mask is wrong, which breaks multi-BSS
operation.

Additionally, the current way of comparing all addresses against each other
is pointless, as the hardware only uses the hardware MAC address and the BSSID
mask for matching the destination address, so all the address array
reallocation is completely unnecessary.

This patch simplifies the logic by setting the initial mask bytes to 0xff
and removing all bits in the iterator call that don't match the hardware MAC
address. It also calls the iterator for the vif that was passed to
add_interface()
Signed-off-by: NFelix Fietkau <nbd@openwrt.org>
Tested-by: NBen Greear <greearb@candelatech.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>