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

Steven Noonan
2008-09-23T16:21:16Z

2008/9/23 Steven Noonan <steven@uplinklabs.net>:> 2008/9/23 Steven Noonan <steven@uplinklabs.net>:>> 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 on>> here 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, it>> should be considered the solution to the issue, unless it resurfaces.>>>> I am only 25 minutes into the run, but I feel this is worth reporting> before I forget. No IRQ storm thus far, but the connection keeps> dropping. Or rather, it doesn't disassociate, but while I was> transferring a large file, it had points of time where it suddenly> lost and reacquired the connection (signal strength fluctuates wildly> between 70-90% and then 0% for a second, and then back to> fluctuating). Perhaps this is related to the lack of aggregation?>
This 8 hour test passes.
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