Kernel Panic in __ieee80211_tx with p43usb as AP

[Larry Finger <Larry.Finger@lwfinger.net>]

In trying to track down a WARNING reported while using p54usb as the
basis for an AP (http://bugzilla.kernel.org/show_bug.cgi?id=13725), I
created an AP using hostapd 0.6.8. It worked fine as long as I used a
Linux client. I ran repeated tcpperf runs through it to my server, and
repeated installations of b43 firmware. That routine uses wget to pull
the driver files. The only machine I had available as a client does
not include X, so I could not run a browser.

All went well until I had a Windows Vista client connect to the
network. As soon as I launched a browser, the kernel on the AP crashed.

The kernel in question is 2.6.31-rc7-Linus-00012-g3edf2fb from the
mainline tree. I do not know the reported reason for the panic, as
that scrolls off the screen. The traceback shows the error to be in
__ieee80211_tx in this statement: ret = drv_tx(local, skb), which
makes the problem be here:

static inline int drv_tx(struct ieee80211_local *local, struct sk_buff
*skb)
{
        return local->ops->tx(&local->hw, skb);
}

Are there any suggest changes that would let me debug this problem
without crashing the kernel?

Thanks,

Larry