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Subject: Re: [PATCH v2 2/3] iommu/tegra-smmu: Rework .probe_device and
 .attach_dev
To:     Nicolin Chen <nicoleotsuka@gmail.com>, thierry.reding@gmail.com,
        joro@8bytes.org, krzk@kernel.org
Cc:     vdumpa@nvidia.com, jonathanh@nvidia.com,
        linux-tegra@vger.kernel.org, iommu@lists.linux-foundation.org,
        linux-kernel@vger.kernel.org
References: <20200930003013.31289-1-nicoleotsuka@gmail.com>
 <20200930003013.31289-3-nicoleotsuka@gmail.com>
From:   Dmitry Osipenko <digetx@gmail.com>
Message-ID: <e557a09b-bcc3-11cb-9529-096aafb42051@gmail.com>
Date:   Wed, 30 Sep 2020 08:39:54 +0300
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30.09.2020 03:30, Nicolin Chen пишет:
>  static int tegra_smmu_attach_dev(struct iommu_domain *domain,
>  				 struct device *dev)
>  {
> +	struct iommu_fwspec *fwspec = dev_iommu_fwspec_get(dev);
>  	struct tegra_smmu *smmu = dev_iommu_priv_get(dev);
>  	struct tegra_smmu_as *as = to_smmu_as(domain);
> -	struct device_node *np = dev->of_node;
> -	struct of_phandle_args args;
>  	unsigned int index = 0;
>  	int err = 0;
>  
> -	while (!of_parse_phandle_with_args(np, "iommus", "#iommu-cells", index,
> -					   &args)) {
> -		unsigned int swgroup = args.args[0];
> -
> -		if (args.np != smmu->dev->of_node) {
> -			of_node_put(args.np);
> -			continue;
> -		}
> -
> -		of_node_put(args.np);
> +	if (!fwspec || fwspec->ops != &tegra_smmu_ops)
> +		return -ENOENT;

s/&tegra_smmu_ops/smmu->iommu.ops/

Secondly, is it even possible that fwspec could be NULL here or that
fwspec->ops != smmu->ops?