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Message-ID: <4e4f630e-adbd-79a9-ea04-6f981d40485e@baylibre.com>
Date:   Wed, 16 Mar 2022 09:32:45 +0100
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Subject: Re: [PATCH v8 05/16] hwrng: meson - Don't open-code
 devm_clk_get_optional_enabled()
Content-Language: en-US
To:     =?UTF-8?Q?Uwe_Kleine-K=c3=b6nig?= <u.kleine-koenig@pengutronix.de>,
        Michael Turquette <mturquette@baylibre.com>,
        Stephen Boyd <sboyd@kernel.org>,
        Russell King <linux@armlinux.org.uk>,
        Matt Mackall <mpm@selenic.com>,
        Herbert Xu <herbert@gondor.apana.org.au>
Cc:     linux-clk@vger.kernel.org, kernel@pengutronix.de,
        Kevin Hilman <khilman@baylibre.com>,
        Jerome Brunet <jbrunet@baylibre.com>,
        Martin Blumenstingl <martin.blumenstingl@googlemail.com>,
        linux-crypto@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
        linux-amlogic@lists.infradead.org
References: <20220314141643.22184-1-u.kleine-koenig@pengutronix.de>
 <20220314141643.22184-6-u.kleine-koenig@pengutronix.de>
From:   Neil Armstrong <narmstrong@baylibre.com>
Organization: Baylibre
In-Reply-To: <20220314141643.22184-6-u.kleine-koenig@pengutronix.de>
Content-Type: text/plain; charset=UTF-8; format=flowed
Content-Transfer-Encoding: 8bit
Precedence: bulk

On 14/03/2022 15:16, Uwe Kleine-König wrote:
> devm_clk_get_enabled() returns a clock prepared and enabled and already
> registers a devm exit handler to disable (and unprepare) the clock.
> 
> Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
> ---
>   drivers/char/hw_random/meson-rng.c | 20 ++------------------
>   1 file changed, 2 insertions(+), 18 deletions(-)
> 
> diff --git a/drivers/char/hw_random/meson-rng.c b/drivers/char/hw_random/meson-rng.c
> index 8bb30282ca46..06db5a93e257 100644
> --- a/drivers/char/hw_random/meson-rng.c
> +++ b/drivers/char/hw_random/meson-rng.c
> @@ -33,16 +33,10 @@ static int meson_rng_read(struct hwrng *rng, void *buf, size_t max, bool wait)
>   	return sizeof(u32);
>   }
>   
> -static void meson_rng_clk_disable(void *data)
> -{
> -	clk_disable_unprepare(data);
> -}
> -
>   static int meson_rng_probe(struct platform_device *pdev)
>   {
>   	struct device *dev = &pdev->dev;
>   	struct meson_rng_data *data;
> -	int ret;
>   
>   	data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
>   	if (!data)
> @@ -54,20 +48,10 @@ static int meson_rng_probe(struct platform_device *pdev)
>   	if (IS_ERR(data->base))
>   		return PTR_ERR(data->base);
>   
> -	data->core_clk = devm_clk_get_optional(dev, "core");
> +	data->core_clk = devm_clk_get_optional_enabled(dev, "core");
>   	if (IS_ERR(data->core_clk))
>   		return dev_err_probe(dev, PTR_ERR(data->core_clk),
> -				     "Failed to get core clock\n");
> -
> -	if (data->core_clk) {
> -		ret = clk_prepare_enable(data->core_clk);
> -		if (ret)
> -			return ret;
> -		ret = devm_add_action_or_reset(dev, meson_rng_clk_disable,
> -					       data->core_clk);
> -		if (ret)
> -			return ret;
> -	}
> +				     "Failed to get enabled core clock\n");
>   
>   	data->rng.name = pdev->name;
>   	data->rng.read = meson_rng_read;

Acked-by: Neil Armstrong <narmstrong@baylibre.com>