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Date:   Sat, 13 Mar 2021 14:52:00 -0800
From:   Nicolin Chen <nicoleotsuka@gmail.com>
To:     Dmitry Osipenko <digetx@gmail.com>
Cc:     Thierry Reding <thierry.reding@gmail.com>,
        Joerg Roedel <joro@8bytes.org>,
        Jonathan Hunter <jonathanh@nvidia.com>,
        Krishna Reddy <vdumpa@nvidia.com>,
        Will Deacon <will@kernel.org>,
        iommu@lists.linux-foundation.org, linux-tegra@vger.kernel.org,
        linux-kernel@vger.kernel.org
Subject: Re: [PATCH v1] iommu/tegra-smmu: Make tegra_smmu_probe_device() to
 handle all IOMMU phandles
Message-ID: <20210313225159.GA11402@Asurada-Nvidia>
References: <20210312155439.18477-1-digetx@gmail.com>
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On Fri, Mar 12, 2021 at 06:54:39PM +0300, Dmitry Osipenko wrote:
> The tegra_smmu_probe_device() handles only the first IOMMU device-tree
> phandle, skipping the rest. Devices like 3D module on Tegra30 have
> multiple IOMMU phandles, one for each h/w block, and thus, only one
> IOMMU phandle is added to fwspec for the 3D module, breaking GPU.
> Previously this problem was masked by tegra_smmu_attach_dev() which
> didn't use the fwspec, but parsed the DT by itself. The previous commit
> to tegra-smmu driver partially reverted changes that caused problems for
> T124 and now we have tegra_smmu_attach_dev() that uses the fwspec and
> the old-buggy variant of tegra_smmu_probe_device() which skips secondary
> IOMMUs.
> 
> Make tegra_smmu_probe_device() not to skip the secondary IOMMUs. This
> fixes a partially attached IOMMU of the 3D module on Tegra30 and now GPU
> works properly once again.
> 
> Fixes: 765a9d1d02b2 ("iommu/tegra-smmu: Fix mc errors on tegra124-nyan")
> Signed-off-by: Dmitry Osipenko <digetx@gmail.com>

Tested-by: Nicolin Chen <nicoleotsuka@gmail.com>