linux-kernel - Re: Automatic clock disabling on clk

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Message-ID: <20150513201230.GT2067@n2100.arm.linux.org.uk>
Date:	Wed, 13 May 2015 21:12:30 +0100
From:	Russell King - ARM Linux <linux@....linux.org.uk>
To:	Stephen Boyd <sboyd@...eaurora.org>
Cc:	Uwe Kleine-König 
	<u.kleine-koenig@...gutronix.de>,
	Mike Turquette <mturquette@...aro.org>,
	Sascha Hauer <s.hauer@...gutronix.de>,
	linux-kernel@...r.kernel.org, kernel@...gutronix.de,
	linux-clk@...r.kernel.org, linux-arm-kernel@...ts.infradead.org
Subject: Re: Automatic clock disabling on clk_put()

On Wed, May 13, 2015 at 12:45:12PM -0700, Stephen Boyd wrote:
> On 05/12/15 23:45, Uwe Kleine-König wrote:
> >
> >> that hard to call clk_disable_unprepare() on a clock at the end of an
> >> error path? Maybe you could add a devm_clk_get_prepare_enable() that
> >> does what you want and then call clk_disable_unprepare on the exit path?
> > You mean clk_disable_unprepare is called in the same function that calls
> > clk_put I assume such that you don't have to do anything in the exit
> > path.
> >
> 
> Yes that's what I mean.

In terms of stopping people doing:

	clk = clk_get(...);
	clk_prepare_enable(clk);
	clk_put(clk);

I think this is a good thing, because it ensures that people can't do
this anymore.

I think you need to audit the code properly first, and fix any instances
of that _before_ posting patches with your idea - let's try to avoid as
much as possible any breakage resulting from this.

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