Re: [ath9k-devel] ath9k: massive unexplained latency in 2.6.27 (rc5, rc6, probably others)

Steven Noonan
2008-09-23T07:23:00Z

On Mon, Sep 22, 2008 at 9:01 AM, Luis R. Rodriguez<lrodriguez@atheros.com> wrote:> On Mon, Sep 22, 2008 at 8:11 AM, Steven Noonan <steven@uplinklabs.net> wrote:>> On Mon, Sep 22, 2008 at 1:06 AM, Luis R. Rodriguez>> <lrodriguez@atheros.com> wrote:>>> Please test the following patch.>>>>>> diff --git a/drivers/net/wireless/ath9k/core.c b/drivers/net/wireless/ath9k/core.c>>> index c262ef2..9a51739 100644>>> --- a/drivers/net/wireless/ath9k/core.c>>> +++ b/drivers/net/wireless/ath9k/core.c>>> @@ -681,10 +681,12 @@ int ath_open(struct ath_softc *sc, struct ath9k_channel *initial_chan)>>> * Enable MIB interrupts when there are hardware phy counters.>>> * Note we only do this (at the moment) for station mode.>>> */>>> +#if 0>>> if (ath9k_hw_phycounters(ah) &&>>> ((sc->sc_ah->ah_opmode == ATH9K_M_STA) ||>>> (sc->sc_ah->ah_opmode == ATH9K_M_IBSS)))>>> sc->sc_imask |= ATH9K_INT_MIB;>>> +#endif>>> /*>>> * Some hardware processes the TIM IE and fires an>>> * interrupt when the TIM bit is set. For hardware>>>>>>> It didn't apply to -rc7, but I managed to apply it manually>> (apparently you made this for wireless-testing?) and added the #if 0.>> After 7 hours uptime with the driver, no apparent interrupt storm.>>>> I'll do more thorough testing later, but I have a 3 hour drive today,>> and some packing to do, so it'll need to wait a bit.>> Yeah I did it for wireless-testing. Good to hear this so far has> solved the issue. I'll port it to 27 and post it once I get your> blessings that this fixed it by a Tested-by.>
Okay. I'm in Seattle now.
Yes, it solved the issue, but surely an #if 0 isn't a proper solution.What's the actual bug here? I'm afraid the meaning of what's going onhere isn't exactly intuitive.
Also, I'm doing an 8 hour run with this patch tonight. Maybe more,depends on when I wake up. ;)
I think if this resolves the issue on two separate ≈8 hour runs, itshould be considered the solution to the issue, unless it resurfaces.
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