ath "stops working" in hostap mode

Sat Feb 2 10:06:52 UTC 2013

Hi,

So what happens when you turn off the devices in question? Do things
settle down?

Adrian

On 1 February 2013 22:45, Lay, Nathan <nsl03 at my.fsu.edu> wrote:
> One last observation, the Roku and the tablet both employ Broadcom Wi-Fi chipsets ...
>
> Lastly, thanks for all your hard work on if_ath and FreeBSD.
>
> Nate
>
> ________________________________________
> From: Lay, Nathan
> Sent: Saturday, February 02, 2013 1:26 AM
> To: Adrian Chadd
> Subject: RE: ath "stops working" in hostap mode
>
> Hi Adrian,
> Ugh, I neglected to provide this updated information:
>
> FreeBSD RADIO.LOCAL 9.1-STABLE FreeBSD 9.1-STABLE #0 r245019: Fri Jan  4 00:02:39 EST 2013     root at RADIO.LOCAL:/usr/obj/usr/src/sys/RADIO  amd64
>
> ath0 at pci0:1:0:0:        class=0x028000 card=0x3a701186 chip=0x0024168c rev=0x01 hdr=0x00
>     vendor     = 'Atheros Communications Inc.'
>     device     = 'AR5008 Wireless Network Adapter'
>     class      = network
>
> ath0: <Atheros 5416> mem 0xfe9f0000-0xfe9fffff irq 16 at device 0.0 on pci1
> ath0: AR5418 mac 12.10 RF2133 phy 8.1
>
> NOTE: I claimed that it worked flawlessly in FreeBSD 8.x (and it did) ... but I did not test 8.x with this kind of device. This bug may manifest itself in 8.x with Roku too. But it does seem to correlate with low power devices. I had introduced a phone and tablet to the network when the problem first appeared (9.0-RELEASE had just been released or was released for a while). I no longer use the tablet and haven't seen this problem in most of the 2012 year.
>
> Best regards,
> Nathan Lay
> ________________________________________
> From: Lay, Nathan
> Sent: Saturday, February 02, 2013 1:16 AM
> To: Adrian Chadd
> Subject: RE: ath "stops working" in hostap mode
>
> Hi Adrian,
> The problem vanished for most of the year and has recently resurfaced. I just introduced a Roku 2 XD onto the network two days ago.  It is a low power device and, as far as I can tell, sits idle on the Wi-Fi network most of the time. The introduction of this device appears to be responsible for ath "stopping."
>
> Just as a recap, the problem NIC is an AR2416 (D-Link DWA 556).  It sometimes drops off of Wi-Fi scans and is unresponsive and requires the driver itself being reloaded to restore service.
>
> One symptom of the problem is that bexmit (from athstats) drops below 5. Once that happens, ath is "stuck" and the driver must be unloaded and loaded again to "unstuck" it. This heuristic is so reliable that I employ a cron script that checks bexmit every minute and it has triggered maybe twice in the entire year of 2012. And it has triggered about 4-5 times since I introduced Roku 2 two days ago.
>
> I hope that this new information is helpful. Since it is now quasi-reproducible, I would be happy to help you collect debug information.
>
> Best regards,
> Nathan Lay
>
> ________________________________________
> From: Lay, Nathan
> Sent: Friday, January 06, 2012 9:01 PM
> To: Adrian Chadd
> Subject: RE: ath "stops working" in hostap mode
>
> It's fine. I'm horrendously busy too! As I said, I never expected immediate responses to my problem.
>
> I'll do what I can and let you know if I find anything.
>
> Best Regards,
> Nathan Lay
>
> ________________________________________
> From: Adrian Chadd [adrian.chadd at gmail.com]
> Sent: Friday, January 06, 2012 5:52 PM
> To: Lay, Nathan
> Subject: Re: ath "stops working" in hostap mode
>
> Hi,
>
> I've not forgotten about this, I'm just working on other things at the moment.
>
> Are you able to try older snapshots of a -HEAD kernel to see where I
> introduced it? I think that's going to be by far the easiest way to
> establish what happened.
>
> Thanks,
>
>
>
> Adrian
>
> On 2 January 2012 14:51, Lay, Nathan <nsl03 at my.fsu.edu> wrote:
>> You'll be delighted/disappointed to know that this still happens when configured to use channel 5:g (as opposed to 5:ht/40).
>>
>> Thought you would like to know.
>>
>> Best Regards,
>> Nathan Lay
>> ________________________________________
>> From: Adrian Chadd [adrian.chadd at gmail.com]
>> Sent: Sunday, January 01, 2012 6:52 PM
>> To: Lay, Nathan
>> Subject: RE: ath "stops working" in hostap mode
>>
>> Hah it's fine! I want it fixed!
>>
>> Thanks for chasing this up with me.
>>
>> Where in the us are you, btw?
>>
>>
>>
>> Adrian
>>
>>
>>
>> Sent from my Palm Pre on AT&T
>>
>> ________________________________
>> On Jan 1, 2012 3:37 PM, Lay, Nathan <nsl03 at my.fsu.edu> wrote:
>>
>> Of course! I hope you don't have the impression that I expect immediate responses!
>>
>> I'll create the PR now.
>>
>> Best Regards,
>> Nathan Lay
>>
>> ________________________________
>> From: Adrian Chadd [adrian.chadd at gmail.com]
>> Sent: Sunday, January 01, 2012 6:34 PM
>> To: Lay, Nathan
>> Subject: RE: ath "stops working" in hostap mode
>>
>> I'm currently out today, lets revisit this tuesday?
>>
>> Please create a pr. :)
>>
>>
>> Adrian
>>
>>
>>
>> Sent from my Palm Pre on AT&T
>>
>> ________________________________
>> On Jan 1, 2012 3:32 PM, Lay, Nathan <nsl03 at my.fsu.edu> wrote:
>>
>> Shall I check out various revisions and try them out?
>>
>> Can you name any SVN revisions that are suspect? It also seems to happen more frequently when debug options are turned on (which is a good thing).
>>
>> Best Regards,
>> Nathan Lay
>>
>> ________________________________
>> From: Adrian Chadd [adrian.chadd at gmail.com]
>> Sent: Sunday, January 01, 2012 6:31 PM
>> To: Lay, Nathan
>> Subject: RE: ath "stops working" in hostap mode
>>
>> Ah good! A regression we can track down.
>>
>>
>> Adrian
>>
>>
>>
>> Sent from my Palm Pre on AT&T
>>
>> ________________________________
>> On Jan 1, 2012 2:15 PM, Lay, Nathan <nsl03 at my.fsu.edu> wrote:
>>
>> Of course! I'll do it today! I promise.
>>
>> However, I should also mention that this bug appears to be introduced. This card was very stable in hostap mode on 8.x. I'm glad that I ran into this problem if there are so few AR5416 users.
>>
>> Best Regards,
>> Nathan Lay
>>
>> ________________________________________
>> From: Adrian Chadd [adrian.chadd at gmail.com]
>> Sent: Sunday, January 01, 2012 5:00 PM
>> To: Lay, Nathan
>> Subject: Re: ath "stops working" in hostap mode
>>
>> On 1 January 2012 13:38, Lay, Nathan <nsl03 at my.fsu.edu> wrote:
>>> Unloading/reloading the module seems to fix it.
>>>
>>> I'll just make a cron job that checks for bexmit <= 5 and fixes the wlan if it happens.
>>
>> That's fine, just please don't forget to create a PR. I'd like to fix
>> the driver so you don't _have_ to unload and reload it.
>> It's also plausible this sort of bug affects later chips too, as the
>> 11n NICs all share code with the AR5416 NIC.
>>
>>
>> Adrian
>>
>>
>>
>
>