2011-08-13 13:39:23

by Jan Sundman

[permalink] [raw]
Subject: Re: [ath9k-devel] Packet loss regression with Atheros AR9280

Hi,

I'm not sure whether you have found a solution to this issue yet but I
thought that I should share my findings. I'm running Arch linux on my
laptop which have the AR9280 and I saw massive packet loss as well.

I noticed however that this _only_ occurred when the laptop was on
battery power. So it seems to be due to some power save functionality
for the card.

"iwconfig wlan0 power off" seems to fix it so I added this to my startup
script and this fixes it. This is of course not a optimal solution but
may point you in the right direction on fixing the problem.

Br,

/Jan

>On 12 August 2011 10:27, Robert O'Callahan ><[email protected]>
wrote:

>> Anything I can get building with this kernel, I guess. Any particular
>> version I should try?

>I'd suggest going back a month at a time
>(http://www.orbit-lab.org/kernel/compat-wireless-2.6/2011/), >try each
>until you find one that works, then report >"compat-wireless X works,
>compat-wireless Y doesn't". That'll be a good way to >test multiple
>copies of the development wireless tree.

>If someone Fedora-clued knows which version(s) of the >wireless code
>are involved with Robert's good and bad behaviour >reports, that'll
>also help.

>Anything to kick-start a git bisect :-)

>Ciao,


>Adrian



2011-08-13 14:15:09

by Richard Schütz

[permalink] [raw]
Subject: Re: [ath9k-devel] Packet loss regression with Atheros AR9280

Am 13.08.2011 13:21, schrieb Jan Sundman:
> Hi,
>
> I'm not sure whether you have found a solution to this issue yet but I
> thought that I should share my findings. I'm running Arch linux on my
> laptop which have the AR9280 and I saw massive packet loss as well.
>
> I noticed however that this _only_ occurred when the laptop was on
> battery power. So it seems to be due to some power save functionality
> for the card.
>
> "iwconfig wlan0 power off" seems to fix it so I added this to my startup
> script and this fixes it. This is of course not a optimal solution but
> may point you in the right direction on fixing the problem.
>
> Br,
>
> /Jan

It looks like I'm having the same issue with an AR9285. In my
university's wireless network the packet loss is noticeable higher with
power management enabled. But at home everything is fine.

--
Regards,
Richard Schütz

2011-08-14 10:13:37

by Robert O'Callahan

[permalink] [raw]
Subject: Re: [ath9k-devel] Packet loss regression with Atheros AR9280

On Sat, Aug 13, 2011 at 11:21 PM, Jan Sundman <[email protected]> wrote:
> "iwconfig wlan0 power off" seems to fix it so I added this to my startup
> script and this fixes it. This is of course not a optimal solution but
> may point you in the right direction on fixing the problem.

That doesn't help with my problem. Thanks for the idea though.

Rob
--
"If we claim to be without sin, we deceive ourselves and the truth is
not in us. If we confess our sins, he is faithful and just and will
forgive us our sins and purify us from all unrighteousness. If we
claim we have not sinned, we make him out to be a liar and his word is
not in us." [1 John 1:8-10]

2011-08-15 14:56:33

by Mohammed Shafi

[permalink] [raw]
Subject: Re: [ath9k-devel] Packet loss regression with Atheros AR9280

On Sat, Aug 13, 2011 at 4:51 PM, Jan Sundman <[email protected]> wrote:
> Hi,
>
> I'm not sure whether you have found a solution to this issue yet but I
> thought that I should share my findings. I'm running Arch linux on my
> laptop which have the AR9280 and I saw massive packet loss as well.

is it an in built card?

>
> I noticed however that this _only_ occurred when the laptop was on
> battery power. So it seems to be due to some power save functionality
> for the card.

if its an in built card, then
this looks like a platform issue, if so please use
http://www.kernel.org/pub/linux/kernel/people/mcgrof/scripts/cpudmalatency.c
http://johannes.sipsolutions.net/files/netlatency.c.txt

>
> "iwconfig wlan0 power off" seems to fix it so I added this to my startup
> script and this fixes it. This is of course not a optimal solution but
> may point you in the right direction on fixing the problem.
>
> Br,
>
> /Jan
>
>>On 12 August 2011 10:27, Robert O'Callahan ><[email protected]>
> wrote:
>
>>> Anything I can get building with this kernel, I guess. Any particular
>>> version I should try?
>
>>I'd suggest going back a month at a time
>>(http://www.orbit-lab.org/kernel/compat-wireless-2.6/2011/), >try each
>>until you find one that works, then report >"compat-wireless X works,
>>compat-wireless Y doesn't". That'll be a good way to >test multiple
>>copies of the development wireless tree.
>
>>If someone Fedora-clued knows which version(s) of the >wireless code
>>are involved with Robert's good and bad behaviour >reports, that'll
>>also help.
>
>>Anything to kick-start a git bisect :-)
>
>>Ciao,
>
>
>>Adrian
>
> _______________________________________________
> ath9k-devel mailing list
> [email protected]
> https://lists.ath9k.org/mailman/listinfo/ath9k-devel
>



--
shafi

2011-08-14 02:48:51

by Adrian Chadd

[permalink] [raw]
Subject: Re: [ath9k-devel] Packet loss regression with Atheros AR9280

On 13 August 2011 22:14, Richard Sch?tz <[email protected]> wrote:

> It looks like I'm having the same issue with an AR9285. In my university's
> wireless network the packet loss is noticeable higher with power management
> enabled. But at home everything is fine.

Can you please file a kernel bugzilla report for this, so it doesn't get lost?


Adrian