1. 24 Jan, 2013 2 commits
    • Johannes Berg's avatar
      mac80211: fix aggregation state with current drivers · 8147dc7f
      Johannes Berg authored
      
      
      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:
       [<c1046e42>] warn_slowpath_common+0x72/0xa0
       [<c1046f13>] warn_slowpath_fmt+0x33/0x40
       [<fddffa17>] iwlagn_tx_skb+0xc47/0xce0 [iwldvm]
       [<fddfcaa3>] iwlagn_mac_tx+0x23/0x40 [iwldvm]
       [<fd8c98b6>] __ieee80211_tx+0xf6/0x3c0 [mac80211]
       [<fd8cbe00>] ieee80211_tx+0xd0/0x100 [mac80211]
       [<fd8cc176>] ieee80211_xmit+0x96/0xe0 [mac80211]
       [<fd8cc578>] ieee80211_subif_start_xmit+0x348/0xc80 [mac80211]
       [<c1445207>] dev_hard_start_xmit+0x337/0x6d0
       [<c145eee9>] sch_direct_xmit+0xa9/0x210
       [<c14462c0>] 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: default avatarJohannes Berg <johannes.berg@intel.com>
      8147dc7f
    • Emmanuel Grumbach's avatar
      mac80211: provide the vif in rssi_callback · 887da917
      Emmanuel Grumbach authored
      
      
      Since drivers can support several BSS / P2P Client
      interfaces, the rssi callback needs to inform the driver
      about the interface teh rssi event relates to.
      Signed-off-by: default avatarEmmanuel Grumbach <emmanuel.grumbach@intel.com>
      Signed-off-by: default avatarJohannes Berg <johannes.berg@intel.com>
      887da917
  2. 18 Jan, 2013 4 commits
  3. 16 Jan, 2013 13 commits
  4. 14 Jan, 2013 1 commit
  5. 11 Jan, 2013 2 commits
  6. 09 Jan, 2013 2 commits
  7. 04 Jan, 2013 4 commits
  8. 03 Jan, 2013 12 commits