linux.git/net/mac80211/tx.c, branch v4.8

mac80211: check skb_linearize() return value

2016-09-14T10:08:33+00:00

The A-MSDU TX code (within TXQs) didn't always check the return value
of skb_linearize() properly, resulting in potentially passing a frag-
list SKB down to the driver even when it said it can't handle it. Fix
that.

Fixes: 6e0456b545456 ("mac80211: add A-MSDU tx support")
Signed-off-by: Johannes Berg

mac80211: fix sequence number assignment for PS response frames

2016-09-12T09:56:49+00:00

When using intermediate queues, sequence number allocation is deferred
until dequeue. This doesn't work for PS response frames, which bypass
those queues.

Signed-off-by: Felix Fietkau 
Signed-off-by: Johannes Berg

mac80211: fix purging multicast PS buffer queue

2016-08-05T12:06:28+00:00

The code currently assumes that buffered multicast PS frames don't have
a pending ACK frame for tx status reporting.
However, hostapd sends a broadcast deauth frame on teardown for which tx
status is requested. This can lead to the "Have pending ack frames"
warning on module reload.
Fix this by using ieee80211_free_txskb/ieee80211_purge_tx_queue.

Cc: stable@vger.kernel.org
Signed-off-by: Felix Fietkau 
Signed-off-by: Johannes Berg

mac80211: fix fq lockdep warnings

2016-06-30T10:07:44+00:00

Some lockdep assertions were not fulfilled and
resulted in a kernel warning/call trace if driver
used intermediate software queues (e.g. ath10k).

Existing code sequences should've guaranteed safety
but it's always good to be extra careful.

The call trace could look like this:

 [ 237.335805] ------------[ cut here ]------------
 [ 237.335852] WARNING: CPU: 3 PID: 1921 at include/net/fq_impl.h:22 fq_flow_dequeue+0xed/0x140 [mac80211]
 [ 237.335855] Modules linked in: ath10k_pci(E-) ath10k_core(E) ath(E) mac80211(E) cfg80211(E)
 [ 237.335913] CPU: 3 PID: 1921 Comm: rmmod Tainted: G        W   E   4.7.0-rc4-wt-ath+ #1377
 [ 237.335916] Hardware name: Hewlett-Packard HP ProBook 6540b/1722, BIOS 68CDD Ver. F.04 01/27/2010
 [ 237.335918]  00200286 00200286 eff85dac c14151e2 f901574e 00000000 eff85de0 c1081075
 [ 237.335928]  c1ab91f0 00000003 00000781 f901574e 00000016 f8fbabad f8fbabad 00000016
 [ 237.335938]  eb24ff60 00000000 ef3886c0 eff85df4 c10810ba 00000009 00000000 00000000
 [ 237.335948] Call Trace:
 [ 237.335953]  [] dump_stack+0x76/0xb4
 [ 237.335957]  [] __warn+0xe5/0x100
 [ 237.336002]  [] ? fq_flow_dequeue+0xed/0x140 [mac80211]
 [ 237.336046]  [] ? fq_flow_dequeue+0xed/0x140 [mac80211]
 [ 237.336053]  [] warn_slowpath_null+0x2a/0x30
 [ 237.336095]  [] fq_flow_dequeue+0xed/0x140 [mac80211]
 [ 237.336137]  [] fq_flow_reset.constprop.56+0x2a/0x90 [mac80211]
 [ 237.336180]  [] fq_reset.constprop.59+0x2a/0x50 [mac80211]
 [ 237.336222]  [] ieee80211_txq_teardown_flows+0x38/0x40 [mac80211]
 [ 237.336258]  [] ieee80211_unregister_hw+0xe4/0x120 [mac80211]
 [ 237.336275]  [] ath10k_mac_unregister+0x16/0x50 [ath10k_core]
 [ 237.336292]  [] ath10k_core_unregister+0x3d/0x90 [ath10k_core]
 [ 237.336301]  [] ath10k_pci_remove+0x36/0xa0 [ath10k_pci]
 [ 237.336307]  [] pci_device_remove+0x38/0xb0
 ...

Fixes: 5caa328e3811 ("mac80211: implement codel on fair queuing flows")
Fixes: fa962b92120b ("mac80211: implement fair queueing per txq")
Tested-by: Kalle Valo 
Reported-by: Kalle Valo 
Signed-off-by: Michal Kazior 
Signed-off-by: Johannes Berg

mac80211: Encrypt "Group addressed privacy" action frames

2016-06-30T10:06:20+00:00

Previously, the action frames to group address was not encrypted. But
[1] "Table 8-38 Category values" indicates "Mesh" and "Multihop" category
action frames should be encrypted (Group addressed privacy == yes). And the
encyption key should be MGTK ([1] 10.13 Group addressed robust management frame
procedures). So this patch modifies the code to make it suitable for spec.

[1] IEEE Std 802.11-2012

Signed-off-by: Masashi Honma 
Signed-off-by: Johannes Berg

mac80211: implement codel on fair queuing flows

2016-06-09T09:45:10+00:00

There is no other limit other than a global
packet count limit when using software queuing.
This means a single flow queue can grow insanely
long. This is particularly bad for TCP congestion
algorithms which requires a little more
sophisticated frame dropping scheme than a mere
headdrop on limit overflow.

Hence apply (a slighly modified, to fit the knobs)
CoDel5 on flow queues. This improves TCP
convergence and stability when combined with
wireless driver which keeps its own tx queue/fifo
at a minimum fill level for given link conditions.

Signed-off-by: Michal Kazior 
Signed-off-by: Johannes Berg

mac80211: implement fair queueing per txq

2016-06-09T09:34:08+00:00

mac80211's software queues were designed to work
very closely with device tx queues. They are
required to make use of 802.11 packet aggregation
easily and efficiently.

Due to the way 802.11 aggregation is designed it
only makes sense to keep fair queuing as close to
hardware as possible to reduce induced latency and
inertia and provide the best flow responsiveness.

This change doesn't translate directly to
immediate and significant gains. End result
depends on driver's induced latency. Best results
can be achieved if driver keeps its own tx
queue/fifo fill level to a minimum.

Signed-off-by: Michal Kazior 
Signed-off-by: Johannes Berg

mac80211: skip netdev queue control with software queuing

2016-06-09T09:31:27+00:00

Qdiscs are designed with no regard to 802.11
aggregation requirements and hand out
packet-by-packet with no guarantee they are
destined to the same tid. This does more bad than
good no matter how fairly a given qdisc may behave
on an ethernet interface.

Software queuing used per-AC netdev subqueue
congestion control whenever a global AC limit was
hit. This meant in practice a single station or
tid queue could starve others rather easily. This
could resonate with qdiscs in a bad way or could
just end up with poor aggregation performance.
Increasing the AC limit would increase induced
latency which is also bad.

Disabling qdiscs by default and performing
taildrop instead of netdev subqueue congestion
control on the other hand makes it possible for
tid queues to fill up "in the meantime" while
preventing stations starving each other.

This increases aggregation opportunities and
should allow software queuing based drivers
achieve better performance by utilizing airtime
more efficiently with big aggregates.

Signed-off-by: Michal Kazior 
Signed-off-by: Johannes Berg

cfg80211: remove enum ieee80211_band

2016-04-12T13:56:15+00:00

This enum is already perfectly aliased to enum nl80211_band, and
the only reason for it is that we get IEEE80211_NUM_BANDS out of
it. There's no really good reason to not declare the number of
bands in nl80211 though, so do that and remove the cfg80211 one.

Signed-off-by: Johannes Berg

Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net

2016-04-09T21:41:41+00:00