HEADSUP: new ath+hal [patch]

Sam Leffler sam at errno.com
Mon Feb 27 11:18:45 PST 2006


Sam Leffler wrote:
> Yamamoto Shigeru wrote:
>> Hi, sam,
>>
>> I install 20060130 current to same note PC to compare 'current 
>> 20060130' and
>> 'current 20060222'.
>> After installing, I watch control message with
>>  'tcpdump -n -i ath0 -y IEEE802_11'.
>>
>> When using '20060130 current', I can watch "Probe request" from my 
>> note PC.
>> But I can't watch "Probe request" when using '20060222 current'.
>>
>> I add 'printf()' to codes and I check when 'IEEE80211_CHAN_PASSIVE' is 
>> set.
>> I found ath_getchannels() at @src/sys/dev/ath/if_ath.c sets
>> 'IEEE80211_CHAN_PASSIVE', because 'CHANNEL_PASSIVE' in channelFlags is 
>> set.
>>
>> I think ath driver send "Probe request" if ignore 'CHANNEL_PASSIVE' in
>> channelFlags.
>> So I add a code to ignore 'CHANNEL_PASSIVE' and to unset
>> 'IEEE80211_CHAN_PASSIVE'.
>> I test this test code at "broadcast SSID in beacon", and my note PC can
>> associate an AP.
>>
>> It seems me current ath hal returns 'CHANNEL_PASSIVE' for all channels.
>> In @src/sys/contrib/dev/ath/ah.h, comment for 'CHANNEL_PASSIVE' is "Only
>> passive scan allowed in the channel".
>> Does it mean my note PC can't send a probe message?
> 
> Thanks for digging.  When you hit a problem like this it's very helpful 
> to know the regulatory domain and country code in your code; sysctl 
> dev.ath.0 will show that.
> 
> When a channel is marked for passive scan a station cannot send frames 
> unless it knows the channel is being used for 802.11 traffic.  What we 
> need to do is listen first then if we see 802.11 traffic mark the 
> channel as "ok to transmit on".  Then the next time we come to the 
> channel we'll be able to send a probe request frame.  I've been meaning 
> to get that code into cvs for a while; I'll see about making that happen.
> 
> In the meantime you may be able to specify the ap's bssid to associate 
> (can't recall if the current scanning code requires an ssid match and 
> bssid is just used to discriminate between multiple ap's with the same 
> ssid).

Please try the attached patch against head.

	Sam
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