Re: [PATCH RFC 2/6] gpio: mvebu: honour EPROBE_DEFER for devm_clk_get() - Uwe Kleine-König

From: "Uwe Kleine-König" <u.kleine-koenig@pengutronix.de>
To: Russell King <rmk+kernel@armlinux.org.uk>
Cc: Andrew Lunn <andrew@lunn.ch>,
	Bartosz Golaszewski <bgolaszewski@baylibre.com>,
	devicetree@vger.kernel.org,
	Gregory Clement <gregory.clement@bootlin.com>,
	Jason Cooper <jason@lakedaemon.net>,
	Linus Walleij <linus.walleij@linaro.org>,
	linux-arm-kernel@lists.infradead.org, linux-gpio@vger.kernel.org,
	linux-pwm@vger.kernel.org, Mark Rutland <mark.rutland@arm.com>,
	Rob Herring <robh+dt@kernel.org>,
	Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com>,
	Thierry Reding <thierry.reding@gmail.com>
Subject: Re: [PATCH RFC 2/6] gpio: mvebu: honour EPROBE_DEFER for devm_clk_get()
Date: Sun, 29 Mar 2020 15:16:59 +0200	[thread overview]
Message-ID: <20200329131659.4hbshjst4ccvje2n@pengutronix.de> (raw)
In-Reply-To: <E1jIVU9-0005h4-QU@rmk-PC.armlinux.org.uk>

On Sun, Mar 29, 2020 at 11:48:09AM +0100, Russell King wrote:
> Honour deferred probing for devm_clk_get() so that we can get the clock
> for PWM.
> 
> Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
> ---
>  drivers/gpio/gpio-mvebu.c | 3 +++
>  1 file changed, 3 insertions(+)
> 
> diff --git a/drivers/gpio/gpio-mvebu.c b/drivers/gpio/gpio-mvebu.c
> index fa5641615db6..ee13b11c5298 100644
> --- a/drivers/gpio/gpio-mvebu.c
> +++ b/drivers/gpio/gpio-mvebu.c
> @@ -1132,6 +1132,9 @@ static int mvebu_gpio_probe(struct platform_device *pdev)
>  	}
>  
>  	mvchip->clk = devm_clk_get(&pdev->dev, NULL);
> +	if (mvchip->clk == ERR_PTR(-EPROBE_DEFER))
> +		return -EPROBE_DEFER;
> +
>  	/* Not all SoCs require a clock.*/
>  	if (!IS_ERR(mvchip->clk))
>  		clk_prepare_enable(mvchip->clk);

I'd say the following is the right thing to do here:

	mvchip->clk = devm_clk_get_optional(...);
	if (IS_ERR(mvchip->clk))
		return ...

Best regards
Uwe

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Pengutronix e.K.                           | Uwe Kleine-König            |
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