Even before the recent changes, the documentation
for TX aggregation was somewhat out of date. Update
it and also add documentation for the RX side.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
To prepare for allowing drivers to sleep in
ampdu_action, change the locking in the TX
aggregation code to use the mutex the RX part
already uses. The spinlock is still necessary
around some code to avoid races with TX, but
now we can also synchronize_net() to avoid
getting an inconsistent sequence number.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Since we want the code to be able to sleep
in the future, it must not be called from
the timer directly. To achieve that, simply
call the function drivers would call, and
also use RCU in the timer to get the struct
so we don't need to rely on the spinlock in
the future.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Move the block-ack session works into common
code, since it will be needed for RX agg too
in the next patches.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
When the driver or rate control requests starting
or stopping an aggregation session, that currently
causes a direct callback into the driver, which
could potentially cause locking problems. Also,
the functions need to be callable from contexts
that cannot sleep, and thus will interfere with
making the ampdu_action callback sleeping.
To address these issues, add a new work item for
each station that will process any start or stop
requests out of line.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
mac80211 currently maintains the ampdu_lock to
avoid starting a queue due to one aggregation
session while another aggregation session needs
the queue stopped.
We can do better, however, and instead refcount
the queue stops for this particular purpose,
thus removing the need for the lock. This will
help making ampdu_action able to sleep.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
The non-irqsafe aggregation start/stop done
callbacks are currently only used by ath9k_htc,
and can cause callbacks into the driver again.
This might lead to locking issues, which will
only get worse as we modify locking. To avoid
trouble, remove the non-irqsafe versions and
change ath9k_htc to use those instead.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Currently we allocate some memory for each TX
aggregation session and additionally keep a
state bitmap indicating the state it is in.
By using RCU to protect the pointer, moving
the state into the structure and some locking
trickery we can avoid locking when the TX agg
session is fully operational.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
This moves the aggregation callback processing
to the per-sdata skb queue and a work function
rather than the tasklet.
Unfortunately, this means that it extends the
pkt_type hack to that skb queue. However, it
will enable making ampdu_action API changes
gradually, my current plan is to get rid of
this again by forcing drivers to only return
from ampdu_action() when everything is done,
thus removing the callbacks completely.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
A number of places use RCU locking for accessing
the station list, even though they do not need
to. Use mutex locking instead to prepare for the
locking changes I want to make. The mlme code is
also using a WLAN_STA_DISASSOC flag that has the
same meaning as WLAN_STA_BLOCK_BA, so use that.
While doing so, combine places where we loop
over stations twice, and optimise away some of
the loops by checking if the hardware supports
aggregation at all first.
Also fix a more theoretical race condition: right
now we could resume, set up an aggregation session,
and right after tear it down again due to the code
that is needed for hardware reconfiguration here.
Also mark add a comment to that code marking it as
a workaround.
Finally, remove a pointless aggregation disabling
loop when an interface is stopped, directly after
that we remove all stations from it which will also
disable all aggregation sessions that may still be
active, and does so in a race-free way unlike the
current loop that doesn't block new sessions.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
There's no sense in letting anything but internal
mac80211 functions set the initiator to anything
but WLAN_BACK_INITIATOR, since WLAN_BACK_RECIPIENT
is only valid when we have received a frame from
the peer, which we react to directly in mac80211.
The debugfs code I recently added got this wrong
as well.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
The dialog token allocator has apparently been broken
since b83f4e15 ("mac80211: fix deadlock in sta->lock")
because it got moved out under the spinlock. Fix it.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
One HT debugging printk is missing a newline,
add it.
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
When the addba timer expires but has no work to do,
it should not affect the state machine. If it does,
TX will not see the successfully established and we
can also crash trying to re-establish the session.
Cc: stable@kernel.org [2.6.32, 2.6.33]
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Enhance tracing by adding tracing for a variety of
callbacks that the drivers call, and also for
internal calls (currently limited to queue status).
This can aid debugging what is going on in mac80211
in interaction with drivers, since we can now see
what drivers call and not just what mac80211 calls
in the driver.
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
I want to use it during station destruction as well
so rename it to WLAN_STA_BLOCK_BA which is also the
only use of it now.
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
percpu.h is included by sched.h and module.h and thus ends up being
included when building most .c files. percpu.h includes slab.h which
in turn includes gfp.h making everything defined by the two files
universally available and complicating inclusion dependencies.
percpu.h -> slab.h dependency is about to be removed. Prepare for
this change by updating users of gfp and slab facilities include those
headers directly instead of assuming availability. As this conversion
needs to touch large number of source files, the following script is
used as the basis of conversion.
http://userweb.kernel.org/~tj/misc/slabh-sweep.py
The script does the followings.
* Scan files for gfp and slab usages and update includes such that
only the necessary includes are there. ie. if only gfp is used,
gfp.h, if slab is used, slab.h.
* When the script inserts a new include, it looks at the include
blocks and try to put the new include such that its order conforms
to its surrounding. It's put in the include block which contains
core kernel includes, in the same order that the rest are ordered -
alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
doesn't seem to be any matching order.
* If the script can't find a place to put a new include (mostly
because the file doesn't have fitting include block), it prints out
an error message indicating which .h file needs to be added to the
file.
The conversion was done in the following steps.
1. The initial automatic conversion of all .c files updated slightly
over 4000 files, deleting around 700 includes and adding ~480 gfp.h
and ~3000 slab.h inclusions. The script emitted errors for ~400
files.
2. Each error was manually checked. Some didn't need the inclusion,
some needed manual addition while adding it to implementation .h or
embedding .c file was more appropriate for others. This step added
inclusions to around 150 files.
3. The script was run again and the output was compared to the edits
from #2 to make sure no file was left behind.
4. Several build tests were done and a couple of problems were fixed.
e.g. lib/decompress_*.c used malloc/free() wrappers around slab
APIs requiring slab.h to be added manually.
5. The script was run on all .h files but without automatically
editing them as sprinkling gfp.h and slab.h inclusions around .h
files could easily lead to inclusion dependency hell. Most gfp.h
inclusion directives were ignored as stuff from gfp.h was usually
wildly available and often used in preprocessor macros. Each
slab.h inclusion directive was examined and added manually as
necessary.
6. percpu.h was updated not to include slab.h.
7. Build test were done on the following configurations and failures
were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my
distributed build env didn't work with gcov compiles) and a few
more options had to be turned off depending on archs to make things
build (like ipr on powerpc/64 which failed due to missing writeq).
* x86 and x86_64 UP and SMP allmodconfig and a custom test config.
* powerpc and powerpc64 SMP allmodconfig
* sparc and sparc64 SMP allmodconfig
* ia64 SMP allmodconfig
* s390 SMP allmodconfig
* alpha SMP allmodconfig
* um on x86_64 SMP allmodconfig
8. percpu.h modifications were reverted so that it could be applied as
a separate patch and serve as bisection point.
Given the fact that I had only a couple of failures from tests on step
6, I'm fairly confident about the coverage of this conversion patch.
If there is a breakage, it's likely to be something in one of the arch
headers which should be easily discoverable easily on most builds of
the specific arch.
Signed-off-by: Tejun Heo <tj@kernel.org>
Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
In associated state, when bringing an interface down, existing
BA sessions are torn down. When this is in progress, nothing
prevents mac80211 from accepting another BA session start request.
Use a new station flag to fix this.
Signed-off-by: Sujith <Sujith.Manoharan@atheros.com>
Acked-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Make addba_resp_timer aware the HT_AGG_STATE_REQ_STOP_BA_MSK mask
so that when ___ieee80211_stop_tx_ba_session() is issued the timer
will quit. Otherwise when suspend happens before the timer expired,
the timer handler will be called immediately after resume and
messes up driver status.
Signed-off-by: Zhu Yi <yi.zhu@intel.com>
Acked-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
The start_seq_num is taken from the station's tid_seq[tid].
This is fine, except tid_seq sequence counter is shifted
by 4 bits to accommodate for frame fragmentation.
Both (iwlagn & ath9k) were unaffected by this minor glitch,
because they don't read the *ssn for the AMPDU_TX_START action.
Signed-off-by: Christian Lamparter <chunkeey@googlemail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
It's not all that useful to have the vif/sdata pointer,
we'd rather refer to the interfaces by their name.
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
For bluetooth 3, we will most likely not have
a netdev for a virtual interface (sdata), so
prepare for that by reducing the reliance on
having a netdev. This patch moves the name
and address fields into the sdata struct and
uses them from there all over. Some work is
needed to keep them sync'ed, but that's not
a lot of work and in slow paths anyway.
In doing so, this also reduces the number of
pointer dereferences in many places, because
of things like sdata->dev->dev_addr becoming
sdata->vif.addr.
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
The station management currently uses the virtual
interface, but you cannot add the same station to
multiple virtual interfaces if you're communicating
with it in multiple ways.
This restriction should be lifted so that in the
future we can, for instance, support bluetooth 3
with an access point that mac80211 is already
associated to.
We can do that by requiring all sta_info_get users
to provide the virtual interface and making the RX
code aware that an address may match more than one
station struct. Thanks to the previous patches this
one isn't all that large and except for the RX and
TX status paths changes has low complexity.
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Lennert Buytenhek noticed that delBA handling in mac80211
was broken and has remotely triggerable problems, some of
which are due to some code shuffling I did that ended up
changing the order in which things were done -- this was
commit d75636ef9c
Author: Johannes Berg <johannes@sipsolutions.net>
Date: Tue Feb 10 21:25:53 2009 +0100
mac80211: RX aggregation: clean up stop session
and other parts were already present in the original
commit d92684e660
Author: Ron Rindjunsky <ron.rindjunsky@intel.com>
Date: Mon Jan 28 14:07:22 2008 +0200
mac80211: A-MPDU Tx add delBA from recipient support
The first problem is that I moved a BUG_ON before various
checks -- thereby making it possible to hit. As the comment
indicates, the BUG_ON can be removed since the ampdu_action
callback must already exist when the state is != IDLE.
The second problem isn't easily exploitable but there's a
race condition due to unconditionally setting the state to
OPERATIONAL when a delBA frame is received, even when no
aggregation session was ever initiated. All the drivers
accept stopping the session even then, but that opens a
race window where crashes could happen before the driver
accepts it. Right now, a WARN_ON may happen with non-HT
drivers, while the race opens only for HT drivers.
For this case, there are two things necessary to fix it:
1) don't process spurious delBA frames, and be more careful
about the session state; don't drop the lock
2) HT drivers need to be prepared to handle a session stop
even before the session was really started -- this is
true for all drivers (that support aggregation) but
iwlwifi which can be fixed easily. The other HT drivers
(ath9k and ar9170) are behaving properly already.
Reported-by: Lennert Buytenhek <buytenh@marvell.com>
Cc: stable@kernel.org
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Lennert Buytenhek noticed a remotely triggerable problem
in mac80211, which is due to some code shuffling I did
that ended up changing the order in which things were
done -- this was in
commit d75636ef9c
Author: Johannes Berg <johannes@sipsolutions.net>
Date: Tue Feb 10 21:25:53 2009 +0100
mac80211: RX aggregation: clean up stop session
The problem is that the BUG_ON moved before the various
checks, and as such can be triggered.
As the comment indicates, the BUG_ON can be removed since
the ampdu_action callback must already exist when the
state is OPERATIONAL.
A similar code path leads to a WARN_ON in
ieee80211_stop_tx_ba_session, which can also be removed.
Cc: stable@kernel.org [2.6.29+]
Cc: Lennert Buytenhek <buytenh@marvell.com>
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Since the flags moved into skb->cb, there's no
longer a need to have the encrypt bool passed
into the function, anyone who requires it set
to 0 (false) can just set the flag directly.
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Not assigning the vif pointer causes an oops.
This patch fixes it.
Signed-off-by: Sujith <Sujith.Manoharan@atheros.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
The entire aggregation code currently operates on the
hw pointer and station addresses, but that needs to
change to make stations purely per-vif; As one step
preparing for that make the aggregation code callable
with the station, or by the combination of virtual
interface and station address.
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
commit 2171abc586
Author: Johannes Berg <johannes@sipsolutions.net>
Date: Thu Oct 29 08:34:00 2009 +0100
mac80211: fix addba timer
left a problem in there, even if the timer was
never started it could be deleted and then added.
Linus pointed out that del_timer_sync() isn't
actually needed if we make the timer able to
deal with no longer being needed when it gets
queued _while_ we're in the locked section that
also deletes it. For that the timer function only
needs to check the HT_ADDBA_RECEIVED_MSK bit as
well as the HT_ADDBA_REQUESTED_MSK bit, only if
the former is clear should it do anything.
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
The addba timer function acquires the sta spinlock,
but at the same time we try to del_timer_sync() it
under the spinlock which can produce deadlocks.
To fix this, always del_timer_sync() the timer in
ieee80211_process_addba_resp() and add it again
after checking the conditions, if necessary.
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
We splice skbs from the pending queue for a TID
onto the local pending queue when tearing down a
block ack request. This is not necessary unless we
actually have received a request to start a block ack
request (rate control, for example). If we never received
that request we should not be splicing the tid pending
queue as it would be null, causing a panic.
Not sure yet how exactly we allowed through a call when the
tid state does not have at least HT_ADDBA_REQUESTED_MSK set,
that will require some further review as it is not quite
obvious.
For more information see the bug report:
http://bugzilla.kernel.org/show_bug.cgi?id=13922
This fixes this oops:
BUG: unable to handle kernel NULL pointer dereference at 00000030
IP: [<f8806c70>] ieee80211_agg_splice_packets+0x40/0xc0 [mac80211]
*pdpt = 0000000002d1e001 *pde = 0000000000000000
Thread overran stack, or stack corrupted
Oops: 0000 [#1] SMP
last sysfs file: /sys/module/aes_generic/initstate
Modules linked in: <bleh>
Pid: 0, comm: swapper Not tainted (2.6.31-rc5-wl #2) Dell DV051
EIP: 0060:[<f8806c70>] EFLAGS: 00010292 CPU: 0
EIP is at ieee80211_agg_splice_packets+0x40/0xc0 [mac80211]
EAX: 00000030 EBX: 0000004c ECX: 00000003 EDX: 00000000
ESI: c1c98000 EDI: f745a1c0 EBP: c076be58 ESP: c076be38
DS: 007b ES: 007b FS: 00d8 GS: 0000 SS: 0068
Process swapper (pid: 0, ti=c076a000 task=c0709160 task.ti=c076a000)
Stack: <bleh2>
Call Trace:
[<f8806edb>] ? ieee80211_stop_tx_ba_cb+0xab/0x150 [mac80211]
[<f8802f1e>] ? ieee80211_tasklet_handler+0xce/0x110 [mac80211]
[<c04862ff>] ? net_rx_action+0xef/0x1d0
[<c0149378>] ? tasklet_action+0x58/0xc0
[<c014a0f2>] ? __do_softirq+0xc2/0x190
[<c018eb48>] ? handle_IRQ_event+0x58/0x140
[<c01205fe>] ? ack_apic_level+0x7e/0x270
[<c014a1fd>] ? do_softirq+0x3d/0x40
[<c014a345>] ? irq_exit+0x65/0x90
[<c010a6af>] ? do_IRQ+0x4f/0xc0
[<c014a35d>] ? irq_exit+0x7d/0x90
[<c011d547>] ? smp_apic_timer_interrupt+0x57/0x90
[<c01094a9>] ? common_interrupt+0x29/0x30
[<c010fd9e>] ? mwait_idle+0xbe/0x100
[<c0107e42>] ? cpu_idle+0x52/0x90
[<c054b1a5>] ? rest_init+0x55/0x60
[<c077492d>] ? start_kernel+0x315/0x37d
[<c07743ce>] ? unknown_bootoption+0x0/0x1f9
[<c0774099>] ? i386_start_kernel+0x79/0x81
Code: <bleh3>
EIP: [<f8806c70>] ieee80211_agg_splice_packets+0x40/0xc0 [mac80211] SS:ESP 0068:c076be38
CR2: 0000000000000030
Cc: stable@kernel.org
Testedy-by: Jack Lau <jackelectronics@hotmail.com>
Signed-off-by: Luis R. Rodriguez <lrodriguez@atheros.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
With the internal 'pending' queue system in place, we can simply
put packets there instead of pushing them off to the master dev,
getting rid of the master interface completely.
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
addba_req_num[tid] is supposed to have the count of consecutive
addba request attempts on 'tid' which failed. This count is checked
against a retry threshold (3 times) before starting the addba negotiation.
This patch fixes the way this addba count is incremented/reset and thereby
avoids indefinite addba attempts.
Signed-off-by: Vasanthakumar Thiagarajan <vasanth@atheros.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
In order to later add tracing or verifications to the driver
calls mac80211 makes, this patch adds static inline wrappers
for all operations.
All calls are now written as
drv_<op>(local, ...);
instead of
local->ops-><op>(&local->hw, ...);
Where necessary, the wrappers also do existence checking and
return default values as appropriate.
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
This patch removes all the virtual A-MPDU-queue bookkeeping from
mac80211. Curiously, iwlwifi already does its own bookkeeping, so
it doesn't require much changes except where it needs to handle
starting and stopping the queues in mac80211.
To handle the queue stop/wake properly, we rewrite the software
queue number for aggregation frames and internally to iwlwifi keep
track of the queues that map into the same AC queue, and only talk
to mac80211 about the AC queue. The implementation requires calling
two new functions, iwl_stop_queue and iwl_wake_queue instead of the
mac80211 counterparts.
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Cc: Reinette Chattre <reinette.chatre@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Instead of stopping the entire AC queue when enabling aggregation
(which was only done for hardware with aggregation queues) buffer
the packets for each station, and release them to the pending skb
queue once aggregation is turned on successfully.
We get a little more code, but it becomes conceptually simpler and
we can remove the entire virtual queue mechanism from mac80211 in
a follow-up patch.
This changes how mac80211 behaves towards drivers that support
aggregation but have no hardware queues -- those drivers will now
not be handed packets while the aggregation session is being
established, but only after it has been fully established.
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
When TX aggregation becomes operational, we do a number of steps:
1) print a debug message
2) wake the virtual queue
3) notify the driver
Unfortunately, 1) and 3) are only done if the driver is first to
reply to the aggregation request, it is, however, possible that the
remote station replies before the driver! Thus, unify the code for
this and call the new function ieee80211_agg_tx_operational in both
places where TX aggregation can become operational.
Additionally, rename the driver notification from
IEEE80211_AMPDU_TX_RESUME to IEEE80211_AMPDU_TX_OPERATIONAL.
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
When the driver has been notified with a STA_REMOVE, it tears down
the internal ADDBA state. On resume, trying to initiate aggregation would
fail because mac80211 has not cleared the operational state for that <TID,STA>.
This can be fixed by tearing down the existing sessions on a suspend.
Also, the driver can initiate a new BA session when suspend is in progress.
This is fixed by marking the station as being in suspend state and
denying ADDBA requests for such STAs.
Signed-off-by: Sujith <Sujith.Manoharan@atheros.com>
Acked-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
This patch splits out the ibss code and data from managed (station) mode.
The reason to do this is to better separate the state machines, and have
the code be contained better so it gets easier to determine what exactly
a given change will affect, that in turn makes it easier to understand.
This is quite some churn, especially because I split sdata->u.sta into
sdata->u.mgd and sdata->u.ibss, but I think it's easier to maintain that
way. I've also shuffled around some code -- null function sending is only
applicable to managed interfaces so put that into that file, some other
functions are needed from various places so put them into util, and also
rearranged the prototypes in ieee80211_i.h accordingly.
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Hardware with AMPDU queues currently has broken aggregation.
This patch fixes it by making all A-MPDUs go over the regular AC queues,
but keeping track of the hardware queues in mac80211. As a first rough
version, it actually stops the AC queue for extended periods of time,
which can be removed by adding buffering internal to mac80211, but is
currently not a huge problem because people rarely use multiple TIDs
that are in the same AC (and iwlwifi currently doesn't operate as AP).
This is a short-term fix, my current medium-term plan, which I hope to
execute soon as well, but am not sure can finish before .30, looks like
this:
1) rework the internal queuing layer in mac80211 that we use for
fragments if the driver stopped queue in the middle of a fragmented
frame to be able to queue more frames at once (rather than just a
single frame with its fragments)
2) instead of stopping the entire AC queue, queue up the frames in a
per-station/per-TID queue during aggregation session initiation,
when the session has come up take all those frames and put them
onto the queue from 1)
3) push the ampdu queue layer abstraction this patch introduces in
mac80211 into the driver, and remove the virtual queue stuff from
mac80211 again
This plan will probably also affect ath9k in that mac80211 queues the
frames instead of passing them down, even when there are no ampdu queues.
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Essentially consisting of passing the sta_info pointer around,
instead of repeatedly doing hash lookups.
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
