linux-kernel - Re: [alsa-devel] [PATCH 1/5 v4] ASoC: ep93xx-ac97: Fix platform_get_irq's error checking

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Message-ID: <20171120133717.kscrjsb3y7gnvd2t@piout.net>
Date:   Mon, 20 Nov 2017 14:37:17 +0100
From:   Alexandre Belloni <alexandre.belloni@...e-electrons.com>
To:     Arvind Yadav <arvind.yadav.cs@...il.com>
Cc:     lgirdwood@...il.com, broonie@...nel.org, perex@...ex.cz,
        tiwai@...e.com, matthias.bgg@...il.com,
        linux-arm-kernel@...ts.infradead.org,
        linux-mediatek@...ts.infradead.org, linux@...linux.org.uk,
        alsa-devel@...a-project.org, linux-kernel@...r.kernel.org
Subject: Re: [alsa-devel] [PATCH 1/5 v4] ASoC: ep93xx-ac97: Fix
 platform_get_irq's error checking

On 19/11/2017 at 09:45:00 +0530, Arvind Yadav wrote:
> The platform_get_irq() function returns negative if an error occurs.
> zero or positive number on success. platform_get_irq() error checking
> for zero is not correct.
> 
> Signed-off-by: Arvind Yadav <arvind.yadav.cs@...il.com>
> ---
> changes in v2 :
>                irq was unsigned. so changed it to signed.
> changes in v3 :
>               Add failure case '<= 0' instead of '< 0'. IRQ0 is not valid.
> changes in v4 :
>               Return -ENODEV insted of irq.
> 

To ensure this doesn't get applied: platform_get_irq can return
-EPROBE_DEFER and this must be handled properly.

(Or maybe this has never caused anything and never failed at all and
nobody cares).

>  sound/soc/cirrus/ep93xx-ac97.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/sound/soc/cirrus/ep93xx-ac97.c b/sound/soc/cirrus/ep93xx-ac97.c
> index bbf7a92..efeecee 100644
> --- a/sound/soc/cirrus/ep93xx-ac97.c
> +++ b/sound/soc/cirrus/ep93xx-ac97.c
> @@ -365,7 +365,7 @@ static int ep93xx_ac97_probe(struct platform_device *pdev)
>  {
>  	struct ep93xx_ac97_info *info;
>  	struct resource *res;
> -	unsigned int irq;
> +	int irq;
>  	int ret;
>  
>  	info = devm_kzalloc(&pdev->dev, sizeof(*info), GFP_KERNEL);
> @@ -378,7 +378,7 @@ static int ep93xx_ac97_probe(struct platform_device *pdev)
>  		return PTR_ERR(info->regs);
>  
>  	irq = platform_get_irq(pdev, 0);
> -	if (!irq)
> +	if (irq <= 0)
>  		return -ENODEV;
>  
>  	ret = devm_request_irq(&pdev->dev, irq, ep93xx_ac97_interrupt,
> -- 
> 2.7.4
> 
> _______________________________________________
> Alsa-devel mailing list
> Alsa-devel@...a-project.org
> http://mailman.alsa-project.org/mailman/listinfo/alsa-devel

-- 
Alexandre Belloni, Free Electrons
Embedded Linux and Kernel engineering
http://free-electrons.com

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