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From: "Uwe Kleine-König" <u.kleine-koenig@pengutronix.de>
To: Axel Lin <axel.lin@ingics.com>
Cc: "Wolfram Sang" <wsa@the-dreams.de>,
	linux-i2c@vger.kernel.org,
	"Uwe Kleine-König" <kernel@pengutronix.de>
Subject: Re: [PATCH] i2c: efm32: Prevent potential division by zero
Date: Thu, 14 Apr 2016 10:24:56 +0200	[thread overview]
Message-ID: <20160414082456.GK10108@pengutronix.de> (raw)
In-Reply-To: <1460619774.4294.1.camel@ingics.com>

Hello Axel,

On Thu, Apr 14, 2016 at 03:42:54PM +0800, Axel Lin wrote:
> Make sure we don't OOPS in case clock-frequency is set to 0 in a DT. The
> variable set here is later used as a divisor.

This is correct in principle. I thought it's ok to misbehave if the DT
is broken? In this case the current code is just fine.

Best regards
Uwe

> diff --git a/drivers/i2c/busses/i2c-efm32.c b/drivers/i2c/busses/i2c-efm32.c
> index 8eff627..394c695 100644
> --- a/drivers/i2c/busses/i2c-efm32.c
> +++ b/drivers/i2c/busses/i2c-efm32.c
> @@ -389,7 +389,7 @@ static int efm32_i2c_probe(struct platform_device *pdev)
>  	ddata->location = location;
>  
>  	ret = of_property_read_u32(np, "clock-frequency", &frequency);
> -	if (!ret) {
> +	if (!ret && frequency != 0) {
>  		dev_dbg(&pdev->dev, "using frequency %u\n", frequency);
>  	} else {
>  		frequency = 100000;

-- 
Pengutronix e.K.                           | Uwe Kleine-König            |
Industrial Linux Solutions                 | http://www.pengutronix.de/  |

  reply	other threads:[~2016-04-14  8:24 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-04-14  7:42 [PATCH] i2c: efm32: Prevent potential division by zero Axel Lin
2016-04-14  8:24 ` Uwe Kleine-König [this message]
2016-04-14  8:29   ` Axel Lin
2016-04-14  9:06     ` Uwe Kleine-König

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