Emmanuel noticed that when mac80211 stops the queues for aggregation that can leave a packet pending. This packet will be given to the driver after the AMPDU callback, but as a non-aggregated packet which messes up the sequence number etc. I also noticed by looking at the code that if packets are being processed while we clear the WANT_START bit, they might see it cleared already and queue up on tid_tx->pending. If the driver then rejects the new aggregation session we leak the packet. Fix both of these issues by changing this code to not stop the queues at all. Instead, let packets queue up on the tid_tx->pending queue instead of letting them get to the driver, and add code to recover properly in case the driver rejects the session. (The patch looks large because it has to move two functions to before their new use.) Cc: stable@vger.kernel.org Reported-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com> Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: John W. Linville <linville@tuxdriver.com>
This reverts commit f785d83a19bca326f79d127a413e35769afc0105. This was provoking WARNINGs from the iwlegacy drivers. Signed-off-by: John W. Linville <linville@tuxdriver.com>
The rates bitmap for internal scan requests shoud be filled, otherwise there will be probe requests with zero rates supported. Signed-off-by: Simon Wunderlich <siwu@hrz.tu-chemnitz.de> Signed-off-by: Mathias Kretschmer <mathias.kretschmer@fokus.fraunhofer.de> Cc: stable@vger.kernel.org Signed-off-by: John W. Linville <linville@tuxdriver.com>
When a packet is supposed to sent be as an a-MPDU, mac80211 sets IEEE80211_TX_CTL_AMPDU to let the driver know. On the other hand, mac80211 configures the driver for aggregration with the ampdu_action callback. There is race between these two mechanisms since the following scenario can occur when the BA agreement is torn down: Tx softIRQ drv configuration ========== ================= check OPERATIONAL bit Set the TX_CTL_AMPDU bit in the packet clear OPERATIONAL bit stop Tx AGG Pass Tx packet to the driver. In that case the driver would get a packet with TX_CTL_AMPDU set although it has already been notified that the BA session has been torn down. To fix this, we need to synchronize all the Qdisc activity after we cleared the OPERATIONAL bit. After that step, all the following packets will be buffered until the driver reports it is ready to get new packets for this RA / TID. This buffering allows not to run into another race that would send packets with TX_CTL_AMPDU unset while the driver hasn't been requested to tear down the BA session yet. This race occurs in practice and iwlwifi complains with a WARN_ON when it happens. Cc: stable@kernel.org Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com> Reviewed-by: Johannes Berg <johannes@sipsolutions.net> Signed-off-by: John W. Linville <linville@tuxdriver.com>
If addBA responses comes in just after addba_resp_timer has expired mac80211 will still accept it and try to open the aggregation session. This causes drivers to be confused and in some cases even crash. This patch fixes the race condition and makes sure that if addba_resp_timer has expired addBA response is not longer accepted and we do not try to open half-closed session. Cc: stable@vger.kernel.org Signed-off-by: Nikolay Martynov <mar.kolya@gmail.com> [some adjustments] Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: John W. Linville <linville@tuxdriver.com>
Nikolay noticed (by code review) that mac80211 can attempt to stop an aggregation session while it is already being stopped. So to fix it, check whether stop is already being done and bail out if so. Also move setting the STOPPING state into the lock so things are properly atomic. Cc: stable@vger.kernel.org Reported-by: Nikolay Martynov <mar.kolya@gmail.com> Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: John W. Linville <linville@tuxdriver.com>