Since:

commit b23b025f
Author: Ben Greear <greearb@candelatech.com>
Date:   Fri Feb 4 11:54:17 2011 -0800

    mac80211: Optimize scans on current operating channel.

we do not disable PS while going back to operational channel (on
ieee80211_scan_state_suspend) and deffer that until scan finish.
But since we are allowed to send frames, we can send a frame to AP
without PM bit set, so disable PS on AP side. Then when we switch
to off-channel (in ieee80211_scan_state_resume) we do not enable PS.
Hence we are off-channel with PS disabled, frames are not buffered
by AP.

To fix remove offchannel_ps_disable argument and always enable PS when
going off-channel and disable it when going on-channel, like it was
before.

Cc: stable@vger.kernel.org # 2.6.39+
Signed-off-by: NStanislaw Gruszka <sgruszka@redhat.com>
Tested-by: NSeth Forshee <seth.forshee@canonical.com>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

Felix Liao reported that when an interface is set DOWN
while another interface is executing a ROC, the warning
in ieee80211_start_next_roc() (about the first item on
the list having started already) triggers.

This is because ieee80211_roc_purge() calls it even if
it never actually changed the list of ROC items. To fix
this, simply remove the function call. If it is needed
then it will be done by the ieee80211_sw_roc_work()
function when the ROC item that is being removed while
active is cleaned up.

Cc: stable@vger.kernel.org
Reported-by: NFelix Liao <Felix.Liao@watchguard.com>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

As mwifiex (and mac80211 in the software case) are the
only drivers actually implementing remain-on-channel
with channel type, userspace can't be relying on it.
This is the case, as it's used only for P2P operations
right now.

Rather than adding a flag to tell userspace whether or
not it can actually rely on it, simplify all the code
by removing the ability to use different channel types.
Leave only the validation of the attribute, so that if
we extend it again later (with the needed capability
flag), it can't break userspace sending invalid data.
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

Drivers (e.g. wl12xx) might need to know the vif
to roc on (mainly in order to configure the
rx filters correctly).

Add the vif to the op params, and update the current
users (iwlwifi) to use the new api.
Signed-off-by: NEliad Peller <eliad@wizery.com>
[fix hwsim]
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

Instead of using the pointer which can be re-used
fairly quickly due to allocator patterns and then
makes debugging difficult, maintain a counter and
use its value. Since it's a 64-bit value it can't
really wrap, but catch that case anyway since it
most likely points to a bug somewhere.
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

Instead of operating on a single channel only,
use the new channel context infrastructure in
all mac80211 code.

This enables drivers that want to use the new
channel context infrastructure to use multiple
channels, while nothing should change for all
the other drivers that don't support it.

Right now this disables both TX power settings
and spatial multiplexing powersave. Both need
to be re-enabled on a channel context basis.

Additionally, when channel contexts are used
drop the connection when channel switch is
received rather than trying to handle it. This
will have to be improved later.

[With fixes from Eliad and Emmanuel incorporated]
Signed-off-by: NEliad Peller <eliad@wizery.com>
Signed-off-by: NEmmanuel Grumbach <emmanuel.grumbach@intel.com>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

Depending on the driver, channel contexts may be used or
not. If they are used, the driver must have support for
hardware scan and remain-on-channel; otherwise the driver
must not advertise support for multiple channels.

Also prohibit WDS type interfaces when channel contexts
are to be used as there's no clear definition of which
channel they use.
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

Using list_move() instead of list_del() + list_add().

spatch with a semantic match is used to found this problem.
(http://coccinelle.lip6.fr/)
Signed-off-by: NWei Yongjun <yongjun_wei@trendmicro.com.cn>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

After cfg80211 got a P2P Device abstraction, add
support to mac80211. Whether it really is supported
or not will depend on whether or not the driver has
support for it, but mac80211 needs to change to be
able to support drivers that need a P2P Device.
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

roc is destroyed then roc->started is referenced. Keep a local cache.
Signed-off-by: NAlan Cox <alan@linux.intel.com>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

The management frame and remain-on-channel APIs will be
needed in the P2P device abstraction, so move them over
to the new wdev-based APIs. Userspace can still use both
the interface index and wdev identifier for them so it's
backward compatible, but for the P2P Device wdev it will
be able to use the wdev identifier only.
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

This file will contain more soon, so
rename it to just trace.
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

When a remain-on-channel item is deleted, we remove it
from the list and then start the next item. However,
if it wasn't actually the first item then calling
ieee80211_start_next_roc() is wrong as it will start
the first item -- even if that was already started.

Fix the two places that do this and add a warning to
prevent the problem from reoccurring.
Reported-by: NEliad Peller <eliad@wizery.com>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

The 'tell_ap' argument is always true. So that remove it
and simplify the function.
Signed-off-by: NRajkumar Manoharan <rmanohar@qca.qualcomm.com>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

Ilan pointed out to me that ieee80211_start_next_roc()
already calls ieee80211_run_deferred_scan() if the list
of ROC items is empty, so there's no need to call it
again after calling ieee80211_start_next_roc().
Reported-by: NIlan Peer <ilan.peer@intel.com>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

Redesign all the off-channel code, getting rid of
the generic off-channel work concept, replacing
it with a simple remain-on-channel list.

This fixes a number of small issues with the ROC
implementation:
 * offloaded remain-on-channel couldn't be queued,
   now we can queue it as well, if needed
 * in iwlwifi (the only user) offloaded ROC is
   mutually exclusive with scanning, use the new
   queue to handle that case -- I expect that it
   will later depend on a HW flag

The bigger issue though is that there's a bad bug
in the current implementation: if we get a mgmt
TX request while HW roc is active, and this new
request has a wait time, we actually schedule a
software ROC instead since we can't guarantee the
existing offloaded ROC will still be that long.
To fix this, the queuing mechanism was needed.

The queuing mechanism for offloaded ROC isn't yet
optimal, ideally we should add API to have the HW
extend the ROC if needed. We could add that later
but for now use a software implementation.

Overall, this unifies the behaviour between the
offloaded and software-implemented case as much
as possible.
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

The IDLE handling in HW off-channel is broken right
now since we turn off IDLE only when the off-channel
period already started. Therefore, all drivers that
use it today (only iwlwifi!) must support off-channel
while idle, so playing with idle isn't needed at all.

Off-channel in general, since it's no longer used for
authentication/association, shouldn't affect PS, so
also remove that logic.

Also document a small caveat for reporting TX status
from off-channel frames in HW remain-on-channel.
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

When any interface goes down, it could be the one that we
were doing a remain-on-channel with. We therefore need to
cancel the remain-on-channel and flush the related work
structs so they don't run after the interface has been
removed or even destroyed.

It's also possible in this case that an off-channel SKB
was never transmitted, so free it if this is the case.
Note that this can also happen if the driver finishes
the off-channel period without ever starting it.

Cc: stable@kernel.org
Reported-by: NNirav Shah <nirav.j2.shah@intel.com>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

ieee80211_offchannel_enable_all_ps function is no longer used
and looks like its logic is extensively handled in
ieee80211_offchannel_stop_vifs
Signed-off-by: NMohammed Shafi Shajakhan <mohammed@qca.qualcomm.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

If the vif is stopped while it is offchannel (e.g. right
after p2p negotiation) the SDATA_STATE_OFFCHANNEL flag
is never get cleared, resulting in various bad effects
(e.g. GO can't start beaconing).

Fix it by clearing the SDATA_STATE_OFFCHANNEL flag
even if the vif is stopped.
Signed-off-by: NEliad Peller <eliad@wizery.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

The on-channel work optimisations have caused a
number of issues, and the code is unfortunately
very complex and almost impossible to follow.
Instead of attempting to put in more workarounds
let's just remove those optimisations, we can
work on them again later, after we change the
whole auth/assoc design.

This should fix rate_control_send_low() warnings,
see RH bug 731365.

Cc: stable@vger.kernel.org
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Some drivers (e.g. ath9k) assume that it's safe to go into low-power mode
immediately after the idle state changes. To support that, mac80211 even
calls drv_flush() before that happens.
In some instances, mac80211 sent a packet right after recalculating the
idle state, this patch fixes that.
Signed-off-by: NFelix Fietkau <nbd@openwrt.org>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

These files are non modular, but need to export symbols using
the macros now living in export.h -- call out the include so
that things won't break when we remove the implicit presence
of module.h from everywhere.
Signed-off-by: NPaul Gortmaker <paul.gortmaker@windriver.com>

This should decrease un-necessary flushes, on/off channel work,
and channel changes in cases where the only scanned channel is
the current operating channel.

* Removes SCAN_OFF_CHANNEL flag, uses SDATA_STATE_OFFCHANNEL
  and is-scanning flags instead.

* Add helper method to determine if we are currently configured
  for the operating channel.

* Do no blindly go off/on channel in work.c  Instead, only call
  appropriate on/off code when we really need to change channels.
  Always enable offchannel-ps mode when starting work,
  and disable it when we are done.

* Consolidate ieee80211_offchannel_stop_station and
  ieee80211_offchannel_stop_beaconing, call it
  ieee80211_offchannel_stop_vifs instead.

* Accept non-beacon frames when scanning on operating channel.

* Scan state machine optimized to minimize on/off channel
  transitions.  Also, when going on-channel, go ahead and
  re-enable beaconing.  We're going to be there for 200ms,
  so seems like some useful beaconing could happen.
  Always enable offchannel-ps mode when starting software
  scan, and disable it when we are done.

* Grab local->mtx earlier in __ieee80211_scan_completed_finish
  so that we are protected when calling hw_config(), etc.

* Pass probe-responses up the stack if scanning on local
  channel, so that mlme can take a look.
Signed-off-by: NBen Greear <greearb@candelatech.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

When the driver has remain-on-channel offload,
implement off-channel transmission using that
primitive.
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

This allows drivers to support remain-on-channel
offload if they implement smarter timing or need
to use a device implementation like iwlwifi.
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

The beacon monitor should be disabled when going off channel
to prevent spurious warnings and triggering connection
deterioration work such as sending probe requests. Re-enable
the beacon monitor once we come back to the home channel.

This patch has fixes for stable kernels [2.6.34+].

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>

When we go offchannel mac80211 currently leaves alive the
connection idle monitor. This should be instead postponed
until we come back to our home channel, otherwise by the
time we get back to the home channel we could be triggering
unecesary probe requests. For APs that do not respond to
unicast probe requests (Nexus One is a simple example) this
means we essentially get disconnected after the probes
fails.

This patch has stable fixes for kernels [2.6.35+]

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>

Somebody noticed this problem, and I outlined
to them how to fix it, but haven't heard back
from them. So while I was adding the state
field I figured I could use it to fix it.

The problem, as I understand it, is that when
we go offchannel while the driver has a queue
stopped, the driver will likely start draining
the queue and then enable it while offchannel.
This in turn will enable the interface queue,
and that leads to transmitting data frames on
the wrong channel.

Fix this by keeping track of offchannel status
per interface, and not enabling the interface
queues on interfaces that are offchannel when
the driver enables a queue.
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

When ieee80211_offchannel_return is called, it needs to re-enabled TX
queues that have been stopped in ieee80211_offchannel_stop_beaconing or
ieee80211_offchannel_stop_station. It happens if we are doing a scan with an
IBSS interface. In this case, the interface stopped transmitting.
Signed-off-by: NBenoit Papillault <benoit.papillault@free.fr>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

This implements the new remain-on-channel cfg80211
command in mac80211, extending the work interface.

Also change the work purge code to be able to clean
up events properly (pretending they timed out.)
Signed-off-by: NJouni Malinen <jouni.malinen@atheros.com>
Signed-off-by: NJohannes Berg <johannes@sipsolutions.net>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

The off-channel operations for going into power save mode (station
mode) or stop beaconing (AP/IBSS) are not limited to scanning. Move
these into a separate file and allow them to be used for other
purposes, too.
Signed-off-by: NJouni Malinen <jouni.malinen@atheros.com>
Signed-off-by: NJohannes Berg <johannes@sipsolutions.net>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>