On Tue, Sep 14, 2010 at 8:00 AM, Luis R. Rodriguez <lrodriguez@xxxxxxxxxxx> wrote: > When we return to the home channel we were never reseting our beacon > timers, this was casued by the fact that the scanning flag was still > on even after we returned to our home channel. There are also other > reasons why we would get a reset and if we are not off channel > we always need to resynch our beacon timers, because a reset will > clear them. > > For more details refer to: > > http://code.google.com/p/chromium-os/issues/detail?id=5715 > > This bug is a regression introduced on 2.6.36. The order of the > changes are as follows: > > 5ee08656 - Sat Jul 31 - ath9k: prevent calibration during off-channel activity > a0daa0e7 - Tue Jul 27 - Revert "mac80211: fix sw scan bracketing" > 543708be - Fri Jun 18 - mac80211: fix sw scan bracketing > > mcgrof@tux ~/linux-2.6-allstable (git::master)$ git describe \ > --contains 5ee0865615f65f84e6ee9174771a6716c29e08e1 > v2.6.36-rc1~43^2~34^2~22 > > mcgrof@tux ~/linux-2.6-allstable (git::master)$ git describe \ > --contains a0daa0e7592ada797d6835f11529097aabc27ad2 > v2.6.36-rc1~571^2~64^2~13 > > mcgrof@tux ~/linux-2.6-allstable (git::master)$ git describe \ > --contains 543708be320d7df692d24b349ca01a947b340764 > v2.6.36-rc1~571^2~107^2~187 > > So 5ee08656 would have worked if a0daa0e7 was not committed but > it was so this means 5ee08656 was broken since it assumed that > when we were in the channel change routine the scan flag would > be lifted. As it turns out the scan flag will be set when we > are already on the home channel. > > These issues will need to be considered for our solution on > reshifting the scan complete callback location on mac80211 on > current development kernel work. > > This patch has stable fixes which apply down to [2.6.36+] > > Cc: stable@xxxxxxxxxx > Cc: Paul Stewart <pstew@xxxxxxxxxx> > Cc: Amod Bodas <amod.bodas@xxxxxxxxxxx> > Signed-off-by: Luis R. Rodriguez <lrodriguez@xxxxxxxxxxx> > --- > > This v2 clarifies the second to last sentence, on the v1 this > was just jiberish on my first read.. this should clarify what > I meant. > > drivers/net/wireless/ath/ath9k/main.c | 6 ++++-- > 1 files changed, 4 insertions(+), 2 deletions(-) > > diff --git a/drivers/net/wireless/ath/ath9k/main.c b/drivers/net/wireless/ath/ath9k/main.c > index ba029b2..e349619 100644 > --- a/drivers/net/wireless/ath/ath9k/main.c > +++ b/drivers/net/wireless/ath/ath9k/main.c > @@ -258,9 +258,11 @@ int ath_set_channel(struct ath_softc *sc, struct ieee80211_hw *hw, > if (!(sc->sc_flags & (SC_OP_OFFCHANNEL | SC_OP_SCANNING))) { > ath_start_ani(common); > ieee80211_queue_delayed_work(sc->hw, &sc->tx_complete_work, 0); > - ath_beacon_config(sc, NULL); > } > > + if (!(sc->sc_flags & (SC_OP_OFFCHANNEL))) > + ath_beacon_config(sc, NULL); > + Upon further thought this change should just remove the SC_OP_SCANNING flag from above and let the code there run when we are not off channel. Reason is that as I noted above on the commit log entry the scan flag will be set even when we return to the home channel due to the races in mac80211 that were actually fixed by Johannes but later reverted due to issues. Doing the fix this way would also let us re-arm ANI and the tx completion monitor, this was also broken! I'll respin this patch shortly after some basic testing. Luis -- To unsubscribe from this list: send the line "unsubscribe linux-wireless" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
