The mac80211 workqueue exists to enable mac80211 and drivers
to queue their own work on a single threaded workqueue. mac80211
takes care to flush the workqueue during suspend but we never
really had requirements on drivers for how they should use
the workqueue in consideration for suspend.
We extend mac80211 to document how the mac80211 workqueue should
be used, how it should not be used and finally move raw access to
the workqueue to mac80211 only. Drivers and mac80211 use helpers
to queue work onto the mac80211 workqueue:
* ieee80211_queue_work()
* ieee80211_queue_delayed_work()
These helpers will now warn if mac80211 already completed its
suspend cycle and someone is trying to queue work. mac80211
flushes the mac80211 workqueue prior to suspend a few times,
but we haven't taken the care to ensure drivers won't add more
work after suspend. To help with this we add a warning when
someone tries to add work and mac80211 already completed the
suspend cycle.
Drivers should ensure they cancel any work or delayed work
in the mac80211 stop() callback.
Signed-off-by: Luis R. Rodriguez <lrodriguez@atheros.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
When downing interfaces, it's a good idea to tell the driver to
stop sending beacons; that way the driver doesn't need special
code in ops->remove_interface() when it should already handle the
case in bss_info_changed().
This fixes a potential crash with at least ath5k since the vif
pointer will be nullified while beacon interrupts are still active.
Signed-off-by: Bob Copeland <me@bobcopeland.com>
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Jan reported that his b43-based laptop hangs during suspend.
The problem turned out to be mac80211 asking the driver to
stop the hardware before removing interfaces, and interface
removal caused b43 to touch the hardware (while down, which
causes the hang).
This patch fixes mac80211 to do reorder these operations to
have them in the correct order -- first remove interfaces
and then stop the hardware. Some more code is necessary to
be able to do so in a race-free manner, in particular it is
necessary to not process frames received during quiescing.
Fixes http://bugzilla.kernel.org/show_bug.cgi?id=13337.
Reported-by: Jan Scholz <scholz@fias.uni-frankfurt.de>
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
We forgot to cancel all timers in mac80211 when suspending.
In particular we forgot to deal with some things that can
cause hardware reconfiguration -- while it is down.
While at it we go ahead and add a warning in ieee80211_sta_work()
if its run while the suspend->resume cycle is in effect. This
should not happen and if it does it would indicate there is
a bug lurking in either mac80211 or mac80211 drivers.
With this now wpa_supplicant doesn't blink when I go to suspend
and resume where as before there where issues with some timers
running during the suspend->resume cycle. This caused a lot of
incorrect assumptions and would at times bring back the device
in an incoherent, but mostly recoverable, state.
Signed-off-by: Luis R. Rodriguez <lrodriguez@atheros.com>
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
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>
Some hardware defects may require the hardware to be re-initialised
completely from scratch. Drivers would need much information (for
instance the current MAC address, crypto keys, beaconing information,
etc.) stored duplicated from mac80211 to be able to do this, so let
mac80211 help them.
The new ieee80211_restart_hw() function requires the same code as
resuming, so move that code into a new ieee80211_reconfig() function
in util.c and leave only the suspend code in pm.c.
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
In the normal WPA or RSN case keys are only configured after
associating, so we should do that in that order when resuming
as well. It shouldn't really matter since we do not send any
data at either point, but iwlwifi prefers it this way and it
does seem more natural.
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
When mac80211 resumes, it currently doesn't reconfigure the interfaces
entirely and also doesn't reconfigure BSS information -- fix this.
Also, to be able to test this, add a debugfs file that just calls
the suspend/resume code to see what happens when we go through that,
without needing the time-consuming suspend/resume cycle.
(Original version broke the build for CONFIG_PM=n. Define alternative
functions for that situation. -- JWL)
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>
To avoid concurrent manipulations of the sta list (which shouldn't
be possible at this point, but anyway) we need to hold the sta_lock
around iterating the list.
At the same time, we do not need to iterate the list at all if
the driver doesn't want to be notified.
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Acked-by: Bob Copeland <me@bobcopeland.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Even though userland probably cannot submit packets, there might
still be some coming, and that's no good when the driver doesn't
expect them. Stop the queues across suspend/resume.
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Drivers can theoretically queue more work in one of their callbacks
from mac80211 suspend, so let's flush it once more to be on the safe
side, just before calling ->stop().
Signed-off-by: Bob Copeland <me@bobcopeland.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
This patch introduces suspend and resume callbacks to mac80211,
allowing mac80211 to quiesce its state (bringing down interfaces,
removing keys, etc) in preparation for suspend. cfg80211 will call
the suspend hook before the device suspend, and resume hook after
the device resume.
Signed-off-by: Bob Copeland <me@bobcopeland.com>
Acked-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
