Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67;
Date:   Wed, 6 Mar 2019 09:28:10 +0000
From:   Charles Keepax <ckeepax@opensource.cirrus.com>
To:     Steve Twiss <stwiss.opensource@diasemi.com>
CC:     Liam Girdwood <lgirdwood@gmail.com>,
        Mark Brown <broonie@kernel.org>,
        Support Opensource <support.opensource@diasemi.com>,
        LKML <linux-kernel@vger.kernel.org>,
        Cirrus Patches <patches@opensource.cirrus.com>
Subject: Re: [PATCH 12/13] regulator: wm831x isink: Fix notifier mutex lock
 warning
Message-ID: <20190306092810.GH46536@ediswmail.ad.cirrus.com>
References: <cover.1551808797.git.stwiss.opensource@diasemi.com>
 <f3e0a68a956e63e46cfa22de3716ab24f422edf9.1551808797.git.stwiss.opensource@diasemi.com>
MIME-Version: 1.0
Content-Type: text/plain; charset="us-ascii"
Content-Disposition: inline
In-Reply-To: <f3e0a68a956e63e46cfa22de3716ab24f422edf9.1551808797.git.stwiss.opensource@diasemi.com>
User-Agent: Mutt/1.5.21 (2010-09-15)
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

On Tue, Feb 26, 2019 at 03:51:28PM +0000, Steve Twiss wrote:
> The mutex for the regulator_dev must be controlled by the caller of
> the regulator_notifier_call_chain(), as described in the comment
> for that function.
> 
> Failure to mutex lock and unlock surrounding the notifier call results
> in a kernel WARN_ON_ONCE() which will dump a backtrace for the
> regulator_notifier_call_chain() when that function call is first made.
> The mutex can be controlled using the regulator_lock/unlock() API.
> 
> Fixes: d4d6b722e780 ("regulator: Add WM831x ISINK support")
> Suggested-by: Adam Thomson <Adam.Thomson.Opensource@diasemi.com>
> Signed-off-by: Steve Twiss <stwiss.opensource@diasemi.com>
> ---

Acked-by: Charles Keepax <ckeepax@opensource.cirrus.com>

Thanks,
Charles