Re: [PATCH 1/3] ath9k: prevent calibration during off-channel activity

["Luis R. Rodriguez" <lrodriguez@atheros.com>]

On Wed, Jul 28, 2010 at 2:08 PM, Felix Fietkau <nbd@openwrt.org> wrote:
> On 2010-07-28 10:43 PM, Luis R. Rodriguez wrote:
>> On Wed, Jul 28, 2010 at 10:45 AM, Felix Fietkau <nbd@openwrt.org> wrote:
>>> Previously the software scan callback was used to indicate to the hardware,
>>> when it was safe to calibrate. This didn't really work properly, because it
>>> depends on a specific order of software scan callbacks vs. channel changes.
>>> Also, software scans are not the only thing that triggers off-channel
>>> activity, so it's better to use the newly added indication from mac80211 for
>>> this and not use the software scan callback for anything calibration related.
>>>
>>> This fixes at least some of the invalid noise floor readings that I've seen
>>> in AP mode on AR9160
>>
>> Neat!
>>
>>> --- a/drivers/net/wireless/ath/ath9k/main.c
>>> +++ b/drivers/net/wireless/ath/ath9k/main.c
>>> @@ -154,6 +154,27 @@ void ath9k_ps_restore(struct ath_softc *sc)
>>>        spin_unlock_irqrestore(&sc->sc_pm_lock, flags);
>>>  }
>>>        spin_unlock_irqrestore(&sc->sc_pm_lock, flags);
>>>  }
>>>
>>> +static void ath_start_ani(struct ath_common *common)
>>> +{
>>> +       struct ath_hw *ah = common->ah;
>>> +       unsigned long timestamp = jiffies_to_msecs(jiffies);
>>> +       struct ath_softc *sc = (struct ath_softc *) common->priv;
>>> +
>>> +       if (!(sc->sc_flags & SC_OP_ANI_RUN))
>>> +               return;
>>> +
>>> +       if (sc->sc_flags & SC_OP_OFFCHANNEL)
>>> +               return;
>>> +
>>> +       common->ani.longcal_timer = timestamp;
>>> +       common->ani.shortcal_timer = timestamp;
>>> +       common->ani.checkani_timer = timestamp;
>>> +
>>> +       mod_timer(&common->ani.timer,
>>> +                 jiffies +
>>> +                       msecs_to_jiffies((u32)ah->config.ani_poll_interval));
>>> +}
>>
>> I would prefer if you do this sort of code shift in a separate patch.
>> In this case its pretty easy to see the code is the same so I think
>> its fine the way it is now but for next time please. Otherwise looks
>> good, thanks!!
> If it had been a bigger function, I'd have made a separate patch, but I
> figured for something as trivial as this it wouldn't matter.

iw event -t while  pinging and then issuing a scan:

1280354915.820607: wlan32 (phy #0): scan started
1280354920.390438: wlan32 (phy #0): scan finished: 2412 2417 2422 2427
2432 2437 2442 2447 2452 2457 2462 5180 5200 5220 5240 5260 5280 5300
5320 5500 5520 5540 5560 5580 5660 5680 5700 5745 5765 5785 5805 5825,
""
1280354923.103628: wlan32 (phy #0): deauth FOO -> BAR reason 4:
Disassociated due to inactivity
1280354923.103736: wlan32 (phy #0): disconnected (local request)
1280354923.111251: phy #0: regulatory domain change: set to world
roaming by the wireless core upon initialization request

So this seems to re-introduce the same issue I was seeing before.

  Luis