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Subject: Re: [PATCH 01/10] PM / devfreq: strengthen check for freq_table
To:     Samuel Holland <samuel@sholland.org>,
        MyungJoo Ham <myungjoo.ham@samsung.com>,
        Kyungmin Park <kyungmin.park@samsung.com>,
        Maxime Ripard <mripard@kernel.org>,
        Chen-Yu Tsai <wens@csie.org>,
        Jernej Skrabec <jernej.skrabec@gmail.com>,
        Rob Herring <robh+dt@kernel.org>
Cc:     Michael Turquette <mturquette@baylibre.com>,
        Stephen Boyd <sboyd@kernel.org>, devicetree@vger.kernel.org,
        linux-arm-kernel@lists.infradead.org, linux-pm@vger.kernel.org,
        linux-sunxi@lists.linux.dev, linux-kernel@vger.kernel.org
From:   Chanwoo Choi <cw00.choi@samsung.com>
Organization: Samsung Electronics
Message-ID: <4c306d89-836f-a8d3-90ec-ed22641d0e48@samsung.com>
Date:   Thu, 30 Sep 2021 12:58:08 +0900
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        <CGME20210929044259epcas1p45d15a4d7913caa0bf12c18bd55d48a54@epcas1p4.samsung.com>
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On 9/29/21 1:42 PM, Samuel Holland wrote:
> Since commit ea572f816032 ("PM / devfreq: Change return type of
> devfreq_set_freq_table()"), all devfreq devices are expected to have a
> valid freq_table. The devfreq core unconditionally dereferences
> freq_table in the sysfs code and in get_freq_range().
> 
> Therefore, we need to ensure that freq_table is both non-null and
> non-empty (length is > 0). If either check fails, replace the table
> using set_freq_table() or return the error.
> 
> Signed-off-by: Samuel Holland <samuel@sholland.org>
> ---
>  drivers/devfreq/devfreq.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/devfreq/devfreq.c b/drivers/devfreq/devfreq.c
> index 28f3e0ba6cdd..7a8b022ba456 100644
> --- a/drivers/devfreq/devfreq.c
> +++ b/drivers/devfreq/devfreq.c
> @@ -827,7 +827,7 @@ struct devfreq *devfreq_add_device(struct device *dev,
>  		goto err_dev;
>  	}
>  
> -	if (!devfreq->profile->max_state && !devfreq->profile->freq_table) {
> +	if (!devfreq->profile->max_state || !devfreq->profile->freq_table) {
>  		mutex_unlock(&devfreq->lock);
>  		err = set_freq_table(devfreq);
>  		if (err < 0)
> 


Applied it. Thanks.

-- 
Best Regards,
Chanwoo Choi
Samsung Electronics