kernel.git/net/mac80211/agg-tx.c, branch linux-3.18.y

mac80211: introduce refcount for queue_stop_reasons

2014-06-23T12:22:25Z

Sometimes different vifs may be stopping the queues for the same reason (e.g. when several interfaces are performing a channel switch). Instead of using a bitmask for the reasons, use an integer that holds a refcount instead. In order to keep it backwards compatible, introduce a boolean in some functions that tell us whether the queue stopping should be refcounted or not. For now, use not refcounted for all calls to keep it functionally the same as before. Signed-off-by: Luciano Coelho Signed-off-by: Johannes Berg

mac80211: send {ADD,DEL}BA on AC_VO like other mgmt frames, as per spec

2014-02-04T20:48:28Z

ATM, {ADD,DEL}BA and BAR frames are sent on the AC matching the TID of the BA parameters. In the discussion [1] about this patch, Johannes recalled that it fixed some races with the DELBA and indeed this behavior was introduced in [2]. While [2] is right for the BARs, the part queueing the {ADD,DEL}BAs on their BA params TID AC violates the spec and is more a workaround for some drivers. Helmut expressed some concerns wrt such drivers, in particular DELBAs in rt2x00. ATM, DELBAs are sent after a driver has called (hence "purposely") ieee80211_start_tx_ba_cb_irqsafe and Johannes and Emmanuel gave some details wrt intentions behind the split of the IEEE80211_AMPDU_TX_STOP_* given to the driver ampdu_action supposed to call this function, which could prove handy to people trying to do the right thing in faulty drivers (if their fw/hw don't get in their way). [1] http://mid.gmane.org/1390391564-18481-1-git-send-email-karl.beldan@gmail.com [2] Commit: cf6bb79ad828 ("mac80211: Use appropriate TID for sending BAR, ADDBA and DELBA frames") Signed-off-by: Karl Beldan Cc: Helmut Schaa Cc: Emmanuel Grumbach Signed-off-by: Johannes Berg

mac80211: fix aggregation state with current drivers

2013-01-24T14:43:51Z

For drivers that don't actually flush their queues when aggregation stop with the IEEE80211_AMPDU_TX_STOP_FLUSH or IEEE80211_AMPDU_TX_STOP_FLUSH_CONT reasons is done, like iwlwifi or iwlegacy, mac80211 can then transmit on a TID that the driver still considers busy. This happens in the following way: - IEEE80211_AMPDU_TX_STOP_FLUSH requested - driver marks TID as emptying - mac80211 removes tid_tx data, this can copy packets to the TX pending queues and also let new packets through to the driver - driver gets unexpected TX as it wasn't completely converted to the new API In iwlwifi, this lead to the following warning: WARNING: at drivers/net/wireless/iwlwifi/dvm/tx.c:442 iwlagn_tx_skb+0xc47/0xce0 Tx while agg.state = 4 Modules linked in: [...] Pid: 0, comm: kworker/0:0 Tainted: G W 3.1.0 #1 Call Trace: [] warn_slowpath_common+0x72/0xa0 [] warn_slowpath_fmt+0x33/0x40 [] iwlagn_tx_skb+0xc47/0xce0 [iwldvm] [] iwlagn_mac_tx+0x23/0x40 [iwldvm] [] __ieee80211_tx+0xf6/0x3c0 [mac80211] [] ieee80211_tx+0xd0/0x100 [mac80211] [] ieee80211_xmit+0x96/0xe0 [mac80211] [] ieee80211_subif_start_xmit+0x348/0xc80 [mac80211] [] dev_hard_start_xmit+0x337/0x6d0 [] sch_direct_xmit+0xa9/0x210 [] dev_queue_xmit+0x1b0/0x8e0 Fortunately, solving this problem is easy as the station is being destroyed, so such transmit packets can only happen due to races. Instead of trying to close the race just let the race not reach the drivers by making two changes: 1) remove the explicit aggregation session teardown in the managed mode code, the same thing will be done when the station is removed, in __sta_info_destroy. 2) When aggregation stop with AGG_STOP_DESTROY_STA is requested, leave the tid_tx data around as stopped. It will be cleared and freed in cleanup_single_sta later, but until then any racy packets will be put onto the tid_tx pending queue instead of transmitted which is fine since the station is being removed. Signed-off-by: Johannes Berg

mac80211: improve aggregation debug messages

2013-01-18T20:55:15Z

A lot of the aggregation messages don't indicate the station so they're hard to understand if there are multiple sessions in progress. Make that easier by adding the MAC address to most messages. Also add the TID if it wasn't already there. Signed-off-by: Johannes Berg

mac80211: split TX aggregation stop action

2013-01-03T12:01:42Z

When TX aggregation is stopped, there are a few different cases: - connection with the peer was dropped - session stop was requested locally - session stop was requested by the peer - connection was dropped while a session is stopping The behaviour in these cases should be different, if the connection is dropped then the driver should drop all frames, otherwise the frames may continue to be transmitted, aggregated in the case of a locally requested session stop or unaggregated in the case of the peer requesting session stop. Split these different cases so that the driver can act accordingly; however, treat local and remote stop the same way and ask the driver to not send frames as aggregated packets any more. In the case of connection drop, the stop callback the driver is otherwise supposed to call is no longer required. Signed-off-by: Johannes Berg

mac80211: move ieee80211_remove_tid_tx function

2013-01-03T12:01:42Z

To call it from ___ieee80211_stop_tx_ba_session, move the function and dependencies up. Signed-off-by: Johannes Berg

mac80211: split out aggregation TX removal

2013-01-03T12:01:41Z

Create the function ieee80211_remove_tid_tx to call it from ___ieee80211_stop_tx_ba_session later. Signed-off-by: Johannes Berg

mac80211: split aggregation stop by reason

2013-01-03T12:01:41Z

The initiator/tx doesn't really identify why an aggregation session is stopped, give a reason for stopping that more clearly identifies what's going on. This will help tell the driver clearly what is expected of it. Signed-off-by: Johannes Berg

mac80211: warn only once if ampdu_action isn't assigned

2012-12-07T08:12:50Z

New drivers that might not support ampdu_action yet while in development cause a lot of warnings, use WARN_ON_ONCE instead. Signed-off-by: T Krushna Chaitanya Signed-off-by: Johannes Berg

mac80211: introduce IEEE80211_NUM_TIDS and use it

2012-11-19T14:44:00Z

Introduce IEEE80211_NUM_TIDS in the generic 802.11 header file and use it in place of STA_TID_NUM and NUM_RX_DATA_QUEUES which are both really the number of TIDs. Signed-off-by: Johannes Berg