Message-ID: <4974B107.6050701@gmail.com>
Date: Mon, 19 Jan 2009 16:57:43 +0000
From: Jonathan Cameron <Jonathan.Cameron@gmail.com>
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To: Mark Brown <broonie@opensource.wolfsonmicro.com>
CC: Jonathan Cameron <jic23@cam.ac.uk>, Liam Girdwood <lrg@slimlogic.co.uk>,
       LKML <linux-kernel@vger.kernel.org>
Subject: Re: [RFC] Regulator: Add a voltage changed event to notify consumers
References: <495FD46E.8040208@cam.ac.uk> <1231065078.11643.116.camel@vega.slimlogic.co.uk> <4973793D.60803@cam.ac.uk> <20090119152921.GA23444@rakim.wolfsonmicro.main>
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Mark Brown wrote:
> On Sun, Jan 18, 2009 at 06:47:25PM +0000, Jonathan Cameron wrote:
> 
>> -out:
>> +	mutex_unlock(&rdev->mutex);
>> +	_notifier_call_chain(rdev, REGULATOR_EVENT_VOLTAGE_CHANGE, NULL);
>> +	return 0;
>> +out_unlock:
> 
> It'd be nice if we could modify _notifier_call_chain() to push the 
> locking out a bit so we don't need to drop the lock before calling the
> notifier.  On the other hand, for anything that isn't memory mapped or
> GPIO controlled (most regulators are in this category) the cost of the
> I/O is going to make this a non-issue.
Agreed.  On that note, isn't any call to regulator_force_disable
currently going to deadlock? (lock held in regulator_force_disable,
then re-called in _notifier_call_chain.)

I'll have a look into moving the locks out of _notifier_call_chain.

Jonathan

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