Message-ID: <1400850209.4358.31.camel@jlt4.sipsolutions.net> (sfid-20140523_150351_443412_B055A4CA)
Subject: Re: [PATCH v2 3/5] ath10k: drain tx before restarting hw
From: Johannes Berg <johannes@sipsolutions.net>
To: Michal Kazior <michal.kazior@tieto.com>
Cc: Kalle Valo <kvalo@qca.qualcomm.com>,
	"ath10k@lists.infradead.org" <ath10k@lists.infradead.org>,
	linux-wireless <linux-wireless@vger.kernel.org>
Date: Fri, 23 May 2014 15:03:29 +0200
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On Fri, 2014-05-23 at 11:06 +0200, Michal Kazior wrote:

> There's nothing wrong with other thread holding it. Actually that's
> the reason for this very check.
> 
> The point is to prevent ath10k_drain_tx() being called while caller
> (current thread) holds conf_mutex. If it were to hold conf_mutex then
> cancel_work_sync() can deadlock as both workers it tries to stop try
> to get a hold of the lock too.

That seems pointless - lockdep would warn you about that *anyway*
because cancel_work_sync() and friends have proper annotations. Try it
sometime :)

johannes