releases/2.6.36.2/ath9k-fix-regression-on-beacon-loss-after-bgscan.patch

   1 From 52b8ac92496e03d6b5619204d7f3bae6ce6eae45 Mon Sep 17 00:00:00 2001
   2 From: Luis R. Rodriguez <lrodriguez@atheros.com>
   3 Date: Thu, 16 Sep 2010 15:12:27 -0400
   4 Subject: ath9k: fix regression on beacon loss after bgscan
   5
   6 From: Luis R. Rodriguez <lrodriguez@atheros.com>
   7
   8 commit 52b8ac92496e03d6b5619204d7f3bae6ce6eae45 upstream.
   9
  10 When we return to the home channel we were never reseting our beacon
  11 timers, this was casued by the fact that the scanning flag was still
  12 on even after we returned to our home channel. There are also other
  13 reasons why we would get a reset and if we are not off channel
  14 we always need to resynch our beacon timers, because a reset will
  15 clear them.
  16
  17 This bug is a regression introduced on 2.6.36. The order of the
  18 changes are as follows:
  19
  20 5ee08656 - Sat Jul 31 - ath9k: prevent calibration during off-channel activity
  21 a0daa0e7 - Tue Jul 27 - Revert "mac80211: fix sw scan bracketing"
  22 543708be - Fri Jun 18 - mac80211: fix sw scan bracketing
  23
  24 mcgrof@tux ~/linux-2.6-allstable (git::master)$ git describe \
  25         --contains 5ee0865615f65f84e6ee9174771a6716c29e08e1
  26 v2.6.36-rc1~43^2~34^2~22
  27
  28 mcgrof@tux ~/linux-2.6-allstable (git::master)$ git describe \
  29         --contains a0daa0e7592ada797d6835f11529097aabc27ad2
  30 v2.6.36-rc1~571^2~64^2~13
  31
  32 mcgrof@tux ~/linux-2.6-allstable (git::master)$ git describe \
  33         --contains 543708be320d7df692d24b349ca01a947b340764
  34 v2.6.36-rc1~571^2~107^2~187
  35
  36 So 5ee08656 would have worked if a0daa0e7 was not committed but
  37 it was so this means 5ee08656 was broken since it assumed that
  38 when we were in the channel change routine the scan flag would
  39 be lifted. As it turns out the scan flag will be set when we
  40 are already on the home channel.
  41
  42 For more details refer to:
  43
  44 http://code.google.com/p/chromium-os/issues/detail?id=5715
  45
  46 These issues will need to be considered for our solution on
  47 reshifting the scan complete callback location on mac80211 on
  48 current development kernel work.
  49
  50 This patch has stable fixes which apply down to [2.6.36+]
  51
  52 Cc: Paul Stewart <pstew@google.com>
  53 Cc: Amod Bodas <amod.bodas@atheros.com>
  54 Signed-off-by: Luis R. Rodriguez <lrodriguez@atheros.com>
  55 Signed-off-by: John W. Linville <linville@tuxdriver.com>
  56 Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
  57
  58 ---
  59  drivers/net/wireless/ath/ath9k/main.c |    6 ++++--
  60  1 file changed, 4 insertions(+), 2 deletions(-)
  61
  62 --- a/drivers/net/wireless/ath/ath9k/main.c
  63 +++ b/drivers/net/wireless/ath/ath9k/main.c
  64 @@ -257,9 +257,11 @@ int ath_set_channel(struct ath_softc *sc
  65         if (!(sc->sc_flags & (SC_OP_OFFCHANNEL | SC_OP_SCANNING))) {
  66                 ath_start_ani(common);
  67                 ieee80211_queue_delayed_work(sc->hw, &sc->tx_complete_work, 0);
  68 -               ath_beacon_config(sc, NULL);
  69         }
  70
  71 +       if (!(sc->sc_flags & (SC_OP_OFFCHANNEL)))
  72 +               ath_beacon_config(sc, NULL);
  73 +
  74   ps_restore:
  75         ath9k_ps_restore(sc);
  76         return r;
  77 @@ -953,7 +955,7 @@ int ath_reset(struct ath_softc *sc, bool
  78
  79         ath_update_txpow(sc);
  80
  81 -       if (sc->sc_flags & SC_OP_BEACONS)
  82 +       if ((sc->sc_flags & SC_OP_BEACONS) || !(sc->sc_flags & (SC_OP_OFFCHANNEL)))
  83                 ath_beacon_config(sc, NULL);    /* restart beacons */
  84
  85         ath9k_hw_set_interrupts(ah, ah->imask);