panic: bogus long slot station count 0
sam at errno.com
Sat Aug 13 17:02:42 GMT 2005
Michal Mertl wrote:
> I'm getting easy to reproduce INVARIANTS panics on fresh CURRENT.
> The panicing machine has ath0 configured like this: "ifconfig ath0
> 192.168.0.1/24 media auto mode 11b mediaopt hostap ssid mig_ap_xx".
> When I associate to it with a notebook with an ipw card I get later
> several panics with the same INVARIANTS cause - line 2073 in
> The "normal" panic is this scenario - a station connects and then leaves
> (is turned off or something).
> I run '80211debug assoc' and this is what I get before the panic:
> ath0: [00:0c:f1:3e:8b:07] recv probe req
> ath0: [00:0c:f1:3e:8b:07] station associated at aid 1: short preamble,
> long slot time
> ath0: [00:0c:f1:3e:8b:07] station with aid 1 leaves
> After the association was formed I put the ipw0 card 'down' and after
> short while (a minute or so) I received the third message above and the
> panic with the traceback below. I don't understand much what 'short
> preamble' means but I'd expect to see 'S' character in 'ifconfig ath0
> list sta' command output on the AP if the station was really doing
> shoart preamble.
> Output of 'ifconfig ath0 list sta' on the AP before the crash is this:
> ADDR AID CHAN RATE RSSI IDLE TXSEQ RXSEQ CAPS ERP
> 00:0c:f1:3e:8b:07 1 1 1M 25 210 2 208 E 0
Sigh, guess we need to still reference ic_curmode instead of looking at
the channel characteristics (this was a recent change to deal with your
problem with switching mode from 11a->11g w/ a station associated). The
problem is that ic_curmode needs to be completely removed. I've done
this in p4 but the changes are too extensive to commit at this time.
I'll backout the change for now.
Separately, I recently learned that 11g ap mode w/ a mixed bss is
broken. I forgot to update the ERP ie in the beacon frame so 11g
stations are not informed when an 11b sta joins the bss and slot time
and/or protection are altered. I won't get to fix this for a few weeks.
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