Re: [PATCH] iommu/tegra-smmu: Fix mc errors on tegra124-nyan
From: Nicolin Chen <nicoleotsuka@gmail.com>
Date: 2021-03-10 22:20:25
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linux-iommu, lkml
On Wed, Mar 10, 2021 at 11:22:57PM +0300, Dmitry Osipenko wrote:
quoted hunk ↗ jump to hunk
10.03.2021 22:13, Dmitry Osipenko пишет:quoted
I found that this patch introduced a serious regression on Tegra30 using today's linux-next. Tegra30 has two 3d h/w blocks connected in SLI and only one of the blocks is now attached to IOMMU domain, meaning that GPU is unusable now. All 3d, 2d and display devices share the same "DRM" group on Tegra30. Nicolin, please let me know if have any suggestions. I may take a closer look a day later, for now I'll just revert this patch locally. Thanks in advance.Actually, this was easy to fix:diff --git a/drivers/iommu/tegra-smmu.c b/drivers/iommu/tegra-smmu.c index 97eb62f667d2..639d5ceab60b 100644 --- a/drivers/iommu/tegra-smmu.c +++ b/drivers/iommu/tegra-smmu.c@@ -853,8 +853,6 @@ static struct iommu_device*tegra_smmu_probe_device(struct device *dev) if (err < 0) return ERR_PTR(err); - - break;
Hmm..I don't understand why this "break" causes problems on Tegra30. The older versions that used _find()+configure() had it also, e.g.: https://elixir.bootlin.com/linux/v5.9.16/source/drivers/iommu/tegra-smmu.c#L760 Dmitry, do you have any idea?