linux-kernel - Re: [PATCH] iommu/arm-smmu: Axe a useless test in 'arm_smmu_master_alloc

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Message-ID: <de9ee628-9efb-3078-590c-6852be61c7d2@arm.com>
Date:   Mon, 16 Sep 2019 11:46:10 +0100
From:   Robin Murphy <robin.murphy@....com>
To:     Christophe JAILLET <christophe.jaillet@...adoo.fr>,
        will@...nel.org, joro@...tes.org
Cc:     linux-arm-kernel@...ts.infradead.org,
        iommu@...ts.linux-foundation.org, linux-kernel@...r.kernel.org,
        kernel-janitors@...r.kernel.org
Subject: Re: [PATCH] iommu/arm-smmu: Axe a useless test in
 'arm_smmu_master_alloc_smes()'

On 15/09/2019 20:34, Christophe JAILLET wrote:
> 'ommu_group_get_for_dev()' never returns NULL, so this test can be removed.

Nit: typo in the function name.

Otherwise, there definitely used to be some path where a NULL return 
could leak out, so I would have had that in mind at the time I wrote 
this, but apparently I never noticed that that had already been cleaned 
up by the time this got merged.

Reviewed-by: Robin Murphy <robin.murphy@....com>

Thanks,
Robin.

> Signed-off-by: Christophe JAILLET <christophe.jaillet@...adoo.fr>
> ---
>   drivers/iommu/arm-smmu.c | 2 --
>   1 file changed, 2 deletions(-)
> 
> diff --git a/drivers/iommu/arm-smmu.c b/drivers/iommu/arm-smmu.c
> index c3ef0cc8f764..6fae8cdbe985 100644
> --- a/drivers/iommu/arm-smmu.c
> +++ b/drivers/iommu/arm-smmu.c
> @@ -1038,8 +1038,6 @@ static int arm_smmu_master_alloc_smes(struct device *dev)
>   	}
>   
>   	group = iommu_group_get_for_dev(dev);
> -	if (!group)
> -		group = ERR_PTR(-ENOMEM);
>   	if (IS_ERR(group)) {
>   		ret = PTR_ERR(group);
>   		goto out_err;
>