linux-kernel - Re: [PATCH v3 2/3] clocksource/drivers/renesas-ostm: Fix probe error path

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Message-ID: <db9961d5-e075-5dca-3417-023b7b8ba4c1@linaro.org>
Date:   Wed, 7 Aug 2019 20:13:27 +0200
From:   Daniel Lezcano <daniel.lezcano@...aro.org>
To:     Geert Uytterhoeven <geert+renesas@...der.be>,
        Thomas Gleixner <tglx@...utronix.de>
Cc:     Jacopo Mondi <jacopo+renesas@...ndi.org>,
        Chris Brandt <Chris.Brandt@...esas.com>,
        linux-renesas-soc@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH v3 2/3] clocksource/drivers/renesas-ostm: Fix probe error
 path

On 07/08/2019 10:46, Geert Uytterhoeven wrote:
> Fix various issues in the error path of ostm_init():
>   1. Drop error message printing on of_iomap() failure, as the memory
>      allocation core already takes of that,
>   2. Handle irq_of_parse_and_map() failures correctly: it returns
>      unsigned int, hence make irq unsigned int, and zero is an error,
>   3. Propagate/return appropriate error codes instead of -EFAULT.
>   4. Add a missing clk_put(),
>   5. Split the single cleanup block in separate phases, to avoid
>      clk_put() calling WARN() when passed an error pointer.

Does it make sense to convert to timer-of API?

> Signed-off-by: Geert Uytterhoeven <geert+renesas@...der.be>
> ---
> v3:
>   - New.
> ---
>  drivers/clocksource/renesas-ostm.c | 54 ++++++++++++++++--------------
>  1 file changed, 29 insertions(+), 25 deletions(-)
> 
> diff --git a/drivers/clocksource/renesas-ostm.c b/drivers/clocksource/renesas-ostm.c
> index 37c39b901bb12b38..1e22e54d7b0df40d 100644
> --- a/drivers/clocksource/renesas-ostm.c
> +++ b/drivers/clocksource/renesas-ostm.c
> @@ -155,7 +155,7 @@ static irqreturn_t ostm_timer_interrupt(int irq, void *dev_id)
>  	return IRQ_HANDLED;
>  }
>  
> -static int __init ostm_init_clkevt(struct ostm_device *ostm, int irq,
> +static int __init ostm_init_clkevt(struct ostm_device *ostm, unsigned int irq,
>  			unsigned long rate)
>  {
>  	struct clock_event_device *ced = &ostm->ced;
> @@ -185,11 +185,11 @@ static int __init ostm_init_clkevt(struct ostm_device *ostm, int irq,
>  
>  static int __init ostm_init(struct device_node *np)
>  {
> -	struct ostm_device *ostm;
> -	int ret = -EFAULT;
>  	struct clk *ostm_clk = NULL;
> -	int irq;
> +	struct ostm_device *ostm;
>  	unsigned long rate;
> +	unsigned int irq;
> +	int ret;
>  
>  	ostm = kzalloc(sizeof(*ostm), GFP_KERNEL);
>  	if (!ostm)
> @@ -197,27 +197,29 @@ static int __init ostm_init(struct device_node *np)
>  
>  	ostm->base = of_iomap(np, 0);
>  	if (!ostm->base) {
> -		pr_err("ostm: failed to remap I/O memory\n");
> -		goto err;
> +		ret = -ENOMEM;
> +		goto err_free;
>  	}
>  
>  	irq = irq_of_parse_and_map(np, 0);
> -	if (irq < 0) {
> +	if (!irq) {
>  		pr_err("ostm: Failed to get irq\n");
> -		goto err;
> +		ret = -EINVAL;
> +		goto err_unmap;
>  	}
>  
>  	ostm_clk = of_clk_get(np, 0);
>  	if (IS_ERR(ostm_clk)) {
>  		pr_err("ostm: Failed to get clock\n");
>  		ostm_clk = NULL;
> -		goto err;
> +		ret = PTR_ERR(ostm_clk);
> +		goto err_unmap;
>  	}
>  
>  	ret = clk_prepare_enable(ostm_clk);
>  	if (ret) {
>  		pr_err("ostm: Failed to enable clock\n");
> -		goto err;
> +		goto err_clk_put;
>  	}
>  
>  	rate = clk_get_rate(ostm_clk);
> @@ -229,28 +231,30 @@ static int __init ostm_init(struct device_node *np)
>  	 */
>  	if (!system_clock) {
>  		ret = ostm_init_clksrc(ostm, rate);
> +		if (ret)
> +			goto err_clk_disable;
>  
> -		if (!ret) {
> -			ostm_init_sched_clock(ostm, rate);
> -			pr_info("ostm: used for clocksource\n");
> -		}
> -
> +		ostm_init_sched_clock(ostm, rate);
> +		pr_info("ostm: used for clocksource\n");
>  	} else {
>  		ret = ostm_init_clkevt(ostm, irq, rate);
> +		if (ret)
> +			goto err_clk_disable;
>  
> -		if (!ret)
> -			pr_info("ostm: used for clock events\n");
> -	}
> -
> -err:
> -	if (ret) {
> -		clk_disable_unprepare(ostm_clk);
> -		iounmap(ostm->base);
> -		kfree(ostm);
> -		return ret;
> +		pr_info("ostm: used for clock events\n");
>  	}
>  
>  	return 0;
> +
> +err_clk_disable:
> +	clk_disable_unprepare(ostm_clk);
> +err_clk_put:
> +	clk_put(ostm_clk);
> +err_unmap:
> +	iounmap(ostm->base);
> +err_free:
> +	kfree(ostm);
> +	return ret;
>  }
>  
>  TIMER_OF_DECLARE(ostm, "renesas,ostm", ostm_init);
> 


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