The tid aggregation cleanup is a bit fragile, as it discards failed
subframes in some places, and retransmits them in others. This could
block the cleanup of an existing aggregation session, if a retransmission
for a tid is issued, yet the tid is never scheduled again because of
the cleanup state.

Fix this by getting rid of as many subframes as possible, as early
as possible, and immediately transmitting pending subframes as regular
HT frames instead of waiting for the cleanup to complete.

Drop all pending subframes while keeping track of the Block ACK window
during aggregate tx completion to prevent sending out stale subframes,
which could confuse the receiver side.
Signed-off-by: NFelix Fietkau <nbd@openwrt.org>
Cc: stable@kernel.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>

Use ath9k_cmn_get_hw_crypto_keytype() instead which is
already exported and shared, and does exactly the same thing.
Reported-by: NJohannes Berg <johannes@sipsolutions.net>
Signed-off-by: NLuis R. Rodriguez <lrodriguez@atheros.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

I noticed a possible issue in the paused flag management of the
ath_atx_tid data structure. In particular, in a noisy environment and
under heavy load, I observed that the AGGR session establishment could
fail several times consecutively causing values of the paused flag
greater than one for this TID (ath_tx_pause_tid is called more than
once from ath_tx_aggr_start).

Considering that the session for this TID can not be established also
after the mac80211 stack calls the ieee80211_agg_tx_operational() since
the ath_tx_aggr_resume() lowers the paused flag only by one.

This patch also replaces some BUG_ON calls with WARN_ON, as even if
these unlikely conditions happen, it's not fatal enough to justify a
BUG_ON.
Signed-off-by: NLorenzo Bianconi <lorenzo.bianconi83@gmail.com>
Signed-off-by: NFelix Fietkau <nbd@openwrt.org>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

The noise floor history buffer is currently not kept per channel, which
can lead to problems when changing channels from a clean channel to a
noisy one. Also when switching from HT20 to HT40, the noise floor
history buffer is full of measurements, but none of them contain data
for the extension channel, which it needs quite a bit of time to recover
from.

This patch puts all the per-channel calibration data into a single data
structure, and gives the the driver control over whether that is used
per-channel or even not used for some channels.

For ath9k_htc, I decided to keep this per-channel in order to avoid
creating regressions.

For ath9k, the data is kept only for the operating channel, which saves
some space. ath9k_hw takes care of wiping old data when the operating
channel or its channel flags change.
Signed-off-by: NFelix Fietkau <nbd@openwrt.org>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

When an aggregation session is being cleaned up, while the tx status
for some frames is being processed, the TID is flushed and its buffers
are sent out.

Unfortunately that left the pending un-acked frames unprocessed, thus
leaking buffers. Fix this by reordering the code so that those frames
are processed first, before the TID is flushed.
Signed-off-by: NFelix Fietkau <nbd@openwrt.org>
Cc: stable@kernel.org
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Sometimes txq state(txq->stopped) can be marked as started but the actual
queue may not be started (in ATH_WIPHY_SCAN state, for example). Fix this.
Signed-off-by: NVasanthakumar Thiagarajan <vasanth@atheros.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

The patch 'ath9k: fix a buffer leak in A-MPDU completion' addressed the
issue of running out of buffers/descriptors in the tx path if a STA is
deleted while tx status feedback is still pending.
The remaining issue is that the skbs of the buffers are not reclaimed,
leaving a memory leak.
This patch fixes this issue by running the buffers through
ath_tx_complete_buf(), ensuring that the pending frames counter is also
updated.
Signed-off-by: NFelix Fietkau <nbd@openwrt.org>
Cc: stable@kernel.org
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Occasionally the hardware can send out tx status information with the wrong
TID. In that case, the BA status cannot be trusted and the aggregate
must be retransmitted.
Signed-off-by: NFelix Fietkau <nbd@openwrt.org>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

When ath_tx_complete_aggr() is called, it's responsible for returning
all buffers in the linked list. This was not done when the STA lookup
failed, leading to a race condition that could leak a few buffers when
a STA just disconnected.
Fix this by immediately returning all buffers to the free list in this case.
Signed-off-by: NFelix Fietkau <nbd@openwrt.org>
Cc: stable@kernel.org
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

It looks like it might be possible for a TID to be paused, while still
holding some queued buffers, however ath_tx_node_cleanup currently only
iterates over active TIDs.
Fix this by always checking every allocated TID for the STA that is being
cleaned up.
Signed-off-by: NFelix Fietkau <nbd@openwrt.org>
Cc: stable@kernel.org
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

The 'bf_retries' field of the ath_buf structure was used for both
software retries (AMPDU subframes) and hardware retries (legacy
frames). This led to a wrong retry count being reported for the A-MPDU
rate control stats.
This patch changes the code to no longer use bf_retries for reporting
retry counts, but instead always using the real on-chip retry count
from the ath_tx_status.
Additionally, if the first subframe of an A-MPDU was not acked, the tx
status report is submitted along with the first acked subframe, which
may not contain the correct rates in the tx info.
This is easily corrected by saving the tx rate info before looping over
subframes, and then copying it back once the A-MPDU status report is
submitted.
In my tests this change improves throughput visibly.
Signed-off-by: NFelix Fietkau <nbd@openwrt.org>
Reported-by: NBjörn Smedman <bjorn.smedman@venatech.se>
Cc: stable@kernel.org
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Signed-off-by: NVasanthakumar Thiagarajan <vasanth@atheros.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

It is possbile that the transmission of paprd test frame
might not get completed in 100ms if tx is stuck. Freeing
this skb upon timeout in ath_paprd_calibrate() will result
in accessing already freed memory when the associated pending
buffer is drained in txq. This patch fixes this issue.
Signed-off-by: NVasanthakumar Thiagarajan <vasanth@atheros.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

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

ath9k tries to prevent WMM queue tx buffer starvation caused by
traffic on different queues by limiting the number of pending frames
in a tx queue (tracked in the ath_buf structure). This had a leak
issue, because the a skb can be reassigned to a different ath_buf
in the tx path, causing the pending frame counter to become inaccurate.

To fix this, track the number of frames in an array in the softc,
using the mac80211 queue mapping as index.
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>

ath_get_mac80211_qnum() expects the queue 'subtype'
(internal ID for the WMM AC) as argument when looking up
the mac80211 queue, however ath_wake_mac80211_queue provides
txq->axq_qnum instead, which contains the hardware queue
number. Fix this by keeping track of the WMM class ID in
the txq data structure.
Signed-off-by: NFelix Fietkau <nbd@openwrt.org>
Cc: stable@kernel.org
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Because there is a limited number of tx buffers available, once the
queue has been filled to a certain point, ath9k needs to stop accepting
new frames from mac80211. In order to prevent a full WMM queue from
stopping another queue with fewer frames, this patch limits the number
of queued frames to a quarter of the total available tx buffers, minus
some reserved frames to be used for other purposes (e.g. beacons).

Because tx buffers are reserved for frames when they're staged in
software queues as well, the actual queue depth cannot be used for
this, so this patch stores a reference to the tx queue in the ath_buf
struct and keeps track of the total number of pending frames.
Signed-off-by: NFelix Fietkau <nbd@openwrt.org>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Add missing code to handle nullfunc frame completion in
ath_tx_edma_tasklet().
Signed-off-by: NVasanthakumar Thiagarajan <vasanth@atheros.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

This bug was introduced by the following commit

	Author: Vasanthakumar Thiagarajan <vasanth@atheros.com>
	Date:   Thu Apr 15 17:38:46 2010 -0400

	ath9k: Remove ATH9K_TX_SW_ABORTED and introduce a bool for this purpose

Wrong buffer is checked for bf_tx_aborted field in ath_tx_num_badfrms(),
this may result in a rate scaling with wrong feedback (number
of unacked frames in this case). It is the last one in the chain
of buffers for an aggregate frame that should be checked.

Also it misses the initialization of this field in the buffer,
this may lead to a situation where we stop the sw retransmission
of failed subframes associated to this buffer.
Signed-off-by: NVasanthakumar Thiagarajan <vasanth@atheros.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

ath_print in xmit.c should say "Reseting hardware"
instead of Resetting HAL!(since HAL is being fazed out).
dmesg shows:
[ 8660.899624] ath: Failed to stop TX DMA in 100 msec after killing last frame
[ 8660.899676] ath: Unable to stop TxDMA. Reset HAL!
Signed-off-by: NJustin P. Mattock <justinmattock@gmail.com>
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>

Supported only for single stream rates by the hardware
Signed-off-by: NFelix Fietkau <nbd@openwrt.org>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Instead of increasing bits_per_symbol for supporting more streams, keep
it single-stream only and multiply the values by the numer of streams.
Signed-off-by: NFelix Fietkau <nbd@openwrt.org>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Include MCS0-31 and also add SGI for HT20. This makes it
possible to support more different rate combinations with
newer hardware.

Based on a patch by Selvam. T.
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: NVasanthakumar Thiagarajan <vasanth@atheros.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

LDPC is enabled by the rate control if the its determined
that the target peer supports LDPC. We would have already
intersected the HT capabilities so if our peer supports
LDPC so do we.
Signed-off-by: NLuis R. Rodriguez <lrodriguez@atheros.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Signed-off-by: NVasanthakumar Thiagarajan <vasanth@atheros.com>
Signed-off-by: NLuis R. Rodriguez <lrodriguez@atheros.com>
Signed-off-by: NFelix Fietkau <nbd@openwrt.org>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Also add a function to clean up tx status ring.
Signed-off-by: NVasanthakumar Thiagarajan <vasanth@atheros.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Signed-off-by: NVasanthakumar Thiagarajan <vasanth@atheros.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

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

Signed-off-by: NVasanthakumar Thiagarajan <vasanth@atheros.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

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

Signed-off-by: NVasanthakumar Thiagarajan <vasanth@atheros.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Signed-off-by: NVasanthakumar Thiagarajan <vasanth@atheros.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Signed-off-by: NVasanthakumar Thiagarajan <vasanth@atheros.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>