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From: Viresh Kumar <viresh.kumar@linaro.org>
To: Charles Keepax <ckeepax@opensource.wolfsonmicro.com>
Cc: Lee Jones <lee.jones@linaro.org>,
	linaro-kernel@lists.linaro.org, broonie@kernel.org,
	patches@opensource.wolfsonmicro.com,
	linux-kernel@vger.kernel.org
Subject: Re: [PATCH V3] mfd: wm8994-core: Don't use managed regulator bulk get API
Date: Thu, 27 Oct 2016 15:51:02 +0530	[thread overview]
Message-ID: <20161027102102.GE10423@vireshk-i7> (raw)
In-Reply-To: <20161027091413.GI28180@localhost.localdomain>

On 27-10-16, 10:14, Charles Keepax wrote:
> On Thu, Oct 27, 2016 at 09:09:30AM +0530, Viresh Kumar wrote:
> > The kernel WARNs and then crashes today if wm8994_device_init() fails
> > after calling devm_regulator_bulk_get().
> > 
> > That happens because there are multiple devices involved here and the
> > order in which resources are freed isn't correct.
> > 
> > The regulators are added as children of wm8994->dev.
> > devm_regulator_bulk_get() receives wm8994->dev as the device, though it
> > gets the same regulators which were added as children of wm8994->dev
> > earlier.
> > 
> > During failures, the children are removed first and the core eventually
> > calls regulator_unregister() for them. As regulator_put() was never done
> > for them (opposite of devm_regulator_bulk_get()), the kernel WARNs at
> > 
> > 	WARN_ON(rdev->open_count);
> > 
> > And eventually it crashes from debugfs_remove_recursive().
> > 
> > --------x------------------x----------------
> 
> The back track seems to have got really really long again.

Not just that, even the code moved a version back.

Sorry for the noise, the right version is sent now :(

-- 
viresh

      reply	other threads:[~2016-10-27 14:41 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-10-27  3:39 [PATCH V3] mfd: wm8994-core: Don't use managed regulator bulk get API Viresh Kumar
2016-10-27  9:14 ` Charles Keepax
2016-10-27 10:21   ` Viresh Kumar [this message]

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