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Subject: Re: [PATCH 4/5] iommu/tegra-smmu: Add PCI support
To:     Nicolin Chen <nicoleotsuka@gmail.com>, thierry.reding@gmail.com,
        joro@8bytes.org, krzk@kernel.org
Cc:     linux-tegra@vger.kernel.org, linux-kernel@vger.kernel.org,
        iommu@lists.linux-foundation.org, jonathanh@nvidia.com
References: <20200926080719.6822-1-nicoleotsuka@gmail.com>
 <20200926080719.6822-5-nicoleotsuka@gmail.com>
From:   Dmitry Osipenko <digetx@gmail.com>
Message-ID: <b95b69fb-8570-f5dc-c486-b94958f2a791@gmail.com>
Date:   Sun, 27 Sep 2020 01:18:15 +0300
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26.09.2020 11:07, Nicolin Chen пишет:
...
> +#ifdef CONFIG_PCI
> +	if (!iommu_present(&pci_bus_type)) {

Is this iommu_present() check really needed?

> +		pci_request_acs();

Shouldn't pci_request_acs() be invoked *after* bus_set_iommu() succeeds?

> +		err = bus_set_iommu(&pci_bus_type, &tegra_smmu_ops);
> +		if (err < 0) {
> +			bus_set_iommu(&platform_bus_type, NULL);
> +			iommu_device_unregister(&smmu->iommu);
> +			iommu_device_sysfs_remove(&smmu->iommu);
> +			return ERR_PTR(err);
> +		}
> +	}
> +#endif
> +
>  	if (IS_ENABLED(CONFIG_DEBUG_FS))
>  		tegra_smmu_debugfs_init(smmu);
>  
>