From: Johannes Berg <johannes@sipsolutions.net>
To: Michael Buesch <mb@bu3sch.de>
Cc: "linux-wireless@vger.kernel.org" <linux-wireless@vger.kernel.org>,
Felix Fietkau <nbd@openwrt.org>,
Ben Greear <greearb@candelatech.com>
Subject: Re: WARN_ON in ieee80211_scan_completed_finish triggered
Date: Mon, 07 Mar 2011 13:03:20 +0100 [thread overview]
Message-ID: <1299499400.3790.8.camel@jlt3.sipsolutions.net> (raw)
In-Reply-To: <1299498147.5665.3.camel@marge>
On Mon, 2011-03-07 at 12:42 +0100, Michael Buesch wrote:
> > > [ 1182.826599] WARNING: at net/mac80211/scan.c:310 ieee80211_rx_bss_free+0x20c/0x4b8 [mac80211]()
Actually ... It just looks like a race:
The pattern is this:
mutex_lock(&local->mtx);
finish = __ieee80211_scan_completed(&local->hw, true, false);
mutex_unlock(&local->mtx);
...
if (finish)
__ieee80211_scan_completed_finish(&local->hw, false);
scan_completed() does
local->scanning = 0;
return true;
The warning is:
WARN_ON(local->scanning & (SCAN_SW_SCANNING | SCAN_HW_SCANNING));
but I don't see anything that would prevent a new scan from beginning
during the time the mutex isn't locked, since everything is set to 0 or
NULL that would block a new scan, I think?
johannes
next prev parent reply other threads:[~2011-03-07 12:07 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-03-06 20:25 WARN_ON in ieee80211_scan_completed_finish triggered Michael Buesch
2011-03-07 9:51 ` Johannes Berg
2011-03-07 11:42 ` Michael Buesch
2011-03-07 11:44 ` Johannes Berg
2011-03-07 12:03 ` Johannes Berg [this message]
2011-03-07 13:14 ` Johannes Berg
2011-03-07 13:59 ` Michael Buesch
2011-03-07 14:22 ` Stanislaw Gruszka
2011-03-07 14:30 ` Johannes Berg
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