ural driver stalls under FreeBSD7.1

[Nathan Butcher]

Weongyo Jeong wrote:
> On Thu, Feb 26, 2009 at 06:04:17PM -0800, Sam Leffler wrote:
>> Bengt Ahlgren wrote:
>>> Weongyo Jeong <weongyo.jeong at gmail.com> writes:
>>>  
>>>> On Thu, Feb 26, 2009 at 01:20:36PM +0900, Nathan Butcher wrote:
>>>>    
>>>>> I have a Buffalo WLI-U2-KG54-AI wireless USB adaptor.
>>>>> It has been malfunctioning for quite a while under FreeBSD7.0 and 7.1
>>>>>
>>>>> Typically, It works for a while until eventually it stalls data
>>>>> transfers completely. It always seems to do this after an unspecified
>>>>> amount of time.
>>>>>
>>>>> I know the hardware isn't at fault because the device works fine under
>>>>> Linux.
>>>>>      
>>>> Could you please check that `ifconfig <ifname> -bgscan' disabling the
>>>> background scan helps your symptom?
>>> The above sounds like the same problem as this:
>>>
>>> http://lists.freebsd.org/pipermail/freebsd-mobile/2009-February/011376.html
>>> http://lists.freebsd.org/pipermail/freebsd-mobile/2009-February/011343.html
>>>
>>> The problem is in the background scanning logic in sys/net80211.
>> I don't see how you come to this conclusion.  ural is a totally 
>> different driver than ath and so far as I can recall you never found the 
>> cause for your problem w/ ath.  Most of the usb wireless drivers do a 
>> haphazard job of synchronizing async tasks like bg scan with the 
>> foreground tx/rx processing.  This can lead to firmware and/or usb 
>> issues.  ath does not have these issues but I am aware of at least one 
>> problem w/ bg scanning in ath under RELENG_7 (that is not present in HEAD).
> 
> I agree with sam because I saw some cases like stalls during background
> scanning that most of them I think it's caused by H/W miss-operation or
> miss-configuration by mistakes of driver.

I'll do some testing without the bgscan and report back.
(haven't had time recently)