linux-kernel - Re: [PATCH 3/4] dmaengine: ste_dma40: Remove unneeded ERROR and NULL check in ste

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:   Wed, 18 May 2022 09:15:08 +0200
From:   Krzysztof Kozlowski <krzysztof.kozlowski@...aro.org>
To:     Wan Jiabing <wanjiabing@...o.com>, Vinod Koul <vkoul@...nel.org>,
        Orson Zhai <orsonzhai@...il.com>,
        Baolin Wang <baolin.wang7@...il.com>,
        Chunyan Zhang <zhang.lyra@...il.com>,
        Linus Walleij <linus.walleij@...aro.org>,
        dmaengine@...r.kernel.org, linux-kernel@...r.kernel.org,
        linux-arm-kernel@...ts.infradead.org
Subject: Re: [PATCH 3/4] dmaengine: ste_dma40: Remove unneeded ERROR and NULL
 check in ste_dma40

On 16/05/2022 10:41, Wan Jiabing wrote:
> clk_put() already checks ERROR by using IS_ERR.
> clk_disable_unprepare() already checks NULL by using IS_ERR_OR_NULL.
> Remove unneeded NULL check for clk_ret and ERROR check for clk.
> 
> Signed-off-by: Wan Jiabing <wanjiabing@...o.com>
> ---
>  drivers/dma/ste_dma40.c | 10 ++++------
>  1 file changed, 4 insertions(+), 6 deletions(-)
> 
> diff --git a/drivers/dma/ste_dma40.c b/drivers/dma/ste_dma40.c
> index e1827393143f..7d1bf4ae4495 100644
> --- a/drivers/dma/ste_dma40.c
> +++ b/drivers/dma/ste_dma40.c
> @@ -3119,7 +3119,7 @@ static struct d40_base * __init d40_hw_detect_init(struct platform_device *pdev)
>  	clk = clk_get(&pdev->dev, NULL);
>  	if (IS_ERR(clk)) {
>  		d40_err(&pdev->dev, "No matching clock found\n");
> -		goto check_prepare_enabled;
> +		goto disable_unprepare;

This should be rather return PTR_ERR. No need to jump to labels which
are not relevant (even if harmless) for this case. It's a confusing code.

>  	}
>  
>  	clk_ret = clk_prepare_enable(clk);
> @@ -3305,12 +3305,10 @@ static struct d40_base * __init d40_hw_detect_init(struct platform_device *pdev)
>  	iounmap(virtbase);
>   release_region:
>  	release_mem_region(res->start, resource_size(res));
> - check_prepare_enabled:
> -	if (!clk_ret)
>   disable_unprepare:
> -		clk_disable_unprepare(clk);
> -	if (!IS_ERR(clk))
> -		clk_put(clk);
> +	clk_disable_unprepare(clk);
> +	clk_put(clk);
> +
>  	return NULL;
>  }
>  


Best regards,
Krzysztof