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	Thu, 6 Nov 2014 10:39:37 -0500
From: Sujith Manoharan <sujith@msujith.org>
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Date: Thu, 6 Nov 2014 21:10:53 +0530
To: Johannes Berg <johannes@sipsolutions.net>
Cc: Larry Finger <Larry.Finger@lwfinger.net>,
	linux-wireless <linux-wireless@vger.kernel.org>
Subject: Re: New WARNING from mac80211
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Johannes Berg wrote:
> That sounds like the driver is calling ieee80211_start_tx_ba_cb() [*]
> when it was never requested to start aggregation?
> 
> [*] given the stack dump, it's actually calling
> ieee80211_start_tx_ba_cb_irqsafe() which goes off to a workqueue and
> then calls ieee80211_start_tx_ba_cb() from there

I think this is the race described here: https://patchwork.kernel.org/patch/5095061/

I haven't tried any workaround or fix yet, but it looks like this
race can be hit fairly often.

https://dev.openwrt.org/ticket/9654
https://dev.openwrt.org/ticket/11862
https://dev.openwrt.org/ticket/13542

etc. :-)

Sujith