linux-kernel - Re: [PATCH v4 4/7] regulator: axp20x: reset probe data before each probe

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Message-ID: <20140617204449.GD19730@lukather>
Date:	Tue, 17 Jun 2014 22:44:49 +0200
From:	Maxime Ripard <maxime.ripard@...e-electrons.com>
To:	Boris BREZILLON <boris.brezillon@...e-electrons.com>
Cc:	Samuel Ortiz <sameo@...ux.intel.com>,
	Lee Jones <lee.jones@...aro.org>,
	Liam Girdwood <lgirdwood@...il.com>,
	Mark Brown <broonie@...nel.org>,
	Carlo Caione <carlo@...one.org>,
	Shuge <shuge@...winnertech.com>, kevin@...winnertech.com,
	linux-kernel@...r.kernel.org, linux-arm-kernel@...ts.infradead.org,
	devicetree@...r.kernel.org, linux-doc@...r.kernel.org,
	dev@...ux-sunxi.org
Subject: Re: [PATCH v4 4/7] regulator: axp20x: reset probe data before each
 probe

On Tue, Jun 17, 2014 at 09:38:40AM +0200, Boris BREZILLON wrote:
> The init_data and of_node fields of the axp2xx_matches tables are filled
> at each device probe by the axp20x_regulator_parse_dt function (which then
> calls the of_regulator_match function).
> This means we can probe a new device and consider data initialized during
> the probe of another device as valid.
> 
> Reset init_data and of_node field to NULL before each probe in order to
> avoid this kind of issue.
> 
> Signed-off-by: Boris BREZILLON <boris.brezillon@...e-electrons.com>
> ---
>  drivers/regulator/axp20x-regulator.c | 9 +++++++++
>  1 file changed, 9 insertions(+)
> 
> diff --git a/drivers/regulator/axp20x-regulator.c b/drivers/regulator/axp20x-regulator.c
> index 7a30f49..d42bf6d 100644
> --- a/drivers/regulator/axp20x-regulator.c
> +++ b/drivers/regulator/axp20x-regulator.c
> @@ -324,6 +324,15 @@ static int axp20x_regulator_probe(struct platform_device *pdev)
>  		nregulators = AXP20X_REG_ID_MAX;
>  	}
>  
> +	/*
> +	 * Reset matches table (this table might have been modified by a
> +	 * previous AXP2xx device probe).
> +	 */
> +	for (i = 0; i < nmatches; i++) {
> +		matches[i].init_data = NULL;
> +		matches[i].of_node = NULL;
> +	}
> +

That looks rather hackish, especially since we've never been in such a
case yet, since we have a single PMIC in our system.

Can't you just use memzero here?

Maxime

-- 
Maxime Ripard, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com

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