releases/3.6.4/mac80211-call-drv_get_tsf-in-sleepable-context.patch

   1 From 55fabefe3695241e6ccfa0cd4974f3fa497693dc Mon Sep 17 00:00:00 2001
   2 From: Thomas Pedersen <thomas@cozybit.com>
   3 Date: Fri, 5 Oct 2012 17:57:39 -0700
   4 Subject: mac80211: call drv_get_tsf() in sleepable context
   5
   6 From: Thomas Pedersen <thomas@cozybit.com>
   7
   8 commit 55fabefe3695241e6ccfa0cd4974f3fa497693dc upstream.
   9
  10 The call to drv_get/set_tsf() was put on the workqueue to perform tsf
  11 adjustments since that function might sleep. However it ended up inside
  12 a spinlock, whose critical section must be atomic. Do tsf adjustment
  13 outside the spinlock instead, and get rid of a warning.
  14
  15 Signed-off-by: Thomas Pedersen <thomas@cozybit.com>
  16 Signed-off-by: John W. Linville <linville@tuxdriver.com>
  17 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
  18
  19 ---
  20  net/mac80211/mesh_sync.c |    3 +--
  21  1 file changed, 1 insertion(+), 2 deletions(-)
  22
  23 --- a/net/mac80211/mesh_sync.c
  24 +++ b/net/mac80211/mesh_sync.c
  25 @@ -56,7 +56,6 @@ void mesh_sync_adjust_tbtt(struct ieee80
  26         u64 tsfdelta;
  27
  28         spin_lock_bh(&ifmsh->sync_offset_lock);
  29 -
  30         if (ifmsh->sync_offset_clockdrift_max < beacon_int_fraction) {
  31                 msync_dbg(sdata, "TBTT : max clockdrift=%lld; adjusting\n",
  32                           (long long) ifmsh->sync_offset_clockdrift_max);
  33 @@ -69,11 +68,11 @@ void mesh_sync_adjust_tbtt(struct ieee80
  34                 tsfdelta = -beacon_int_fraction;
  35                 ifmsh->sync_offset_clockdrift_max -= beacon_int_fraction;
  36         }
  37 +       spin_unlock_bh(&ifmsh->sync_offset_lock);
  38
  39         tsf = drv_get_tsf(local, sdata);
  40         if (tsf != -1ULL)
  41                 drv_set_tsf(local, sdata, tsf + tsfdelta);
  42 -       spin_unlock_bh(&ifmsh->sync_offset_lock);
  43  }
  44
  45  static void mesh_sync_offset_rx_bcn_presp(struct ieee80211_sub_if_data *sdata,