linux-kernel - Re: [PATCH 2/4] i2c: designware-platdrv: fix unbalanced clk enable and prepare

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Date:	Wed, 20 Apr 2016 15:55:14 +0300
From:	Jarkko Nikula <jarkko.nikula@...ux.intel.com>
To:	Jisheng Zhang <jszhang@...vell.com>,
	andriy.shevchenko@...ux.intel.com, mika.westerberg@...ux.intel.com,
	wsa@...-dreams.de
Cc:	linux-i2c@...r.kernel.org, linux-kernel@...r.kernel.org,
	linux-arm-kernel@...ts.infradead.org
Subject: Re: [PATCH 2/4] i2c: designware-platdrv: fix unbalanced clk enable
 and prepare

On 04/14/2016 03:53 PM, Jisheng Zhang wrote:
> If i2c_dw_probe() fail, we should call i2c_dw_plat_prepare_clk() to
> disable and unprepare the clk, otherwise the clk enable and prepare
> is left unbalanced.
>
> Signed-off-by: Jisheng Zhang <jszhang@...vell.com>
> ---
>   drivers/i2c/busses/i2c-designware-platdrv.c | 2 ++
>   1 file changed, 2 insertions(+)
>
> diff --git a/drivers/i2c/busses/i2c-designware-platdrv.c b/drivers/i2c/busses/i2c-designware-platdrv.c
> index 00f9e99..1488cea 100644
> --- a/drivers/i2c/busses/i2c-designware-platdrv.c
> +++ b/drivers/i2c/busses/i2c-designware-platdrv.c
> @@ -268,6 +268,8 @@ rpm_disable:
>   		pm_runtime_put_noidle(&pdev->dev);
>   	}
>
> +	i2c_dw_plat_prepare_clk(dev, false);
> +
>   	return r;
>   }
>
This is a bit unclear to me does devm_clk_get take care of clk disabling 
in case of probe error or driver removal?

I see Andy's 1cb715ca4694 ("i2c-designware: move to managed functions 
(devm_*)") removed it but at quick look drivers/clk/clk-devres.c: 
devm_clk_release() calls only clk_put and I don't see disable is done 
down the path.

-- 
Jarkko