From: Jason Gunthorpe Date: Tue, 30 Jan 2024 16:14:54 +0000 (-0400) Subject: drm/tegra: Do not assume that a NULL domain means no DMA IOMMU X-Git-Tag: v6.8-rc3~19^2~1 X-Git-Url: https://git.kernel.dk/?a=commitdiff_plain;h=fae6e669cdc52fdbb843e7fb1b8419642b6b8cba;p=linux-block.git drm/tegra: Do not assume that a NULL domain means no DMA IOMMU Previously with tegra-smmu, even with CONFIG_IOMMU_DMA, the default domain could have been left as NULL. The NULL domain is specially recognized by host1x_client_iommu_attach() as meaning it is not the DMA domain and should be replaced with the special shared domain. This happened prior to the below commit because tegra-smmu was using the NULL domain to mean IDENTITY. Now that the domain is properly labled the test in DRM doesn't see NULL. Check for IDENTITY as well to enable the special domains. Fixes: c8cc2655cc6c ("iommu/tegra-smmu: Implement an IDENTITY domain") Reported-by: diogo.ivo@tecnico.ulisboa.pt Closes: https://lore.kernel.org/all/bbmhcoghrprmbdibnjum6lefix2eoquxrde7wyqeulm4xabmlm@b6jy32saugqh/ Tested-by: diogo.ivo@tecnico.ulisboa.pt Signed-off-by: Jason Gunthorpe Link: https://lore.kernel.org/r/0-v1-3049f92c4812+16691-host1x_def_dom_fix_jgg@nvidia.com Signed-off-by: Joerg Roedel --- diff --git a/drivers/gpu/drm/tegra/drm.c b/drivers/gpu/drm/tegra/drm.c index ff36171c8fb7..a73cff7a3070 100644 --- a/drivers/gpu/drm/tegra/drm.c +++ b/drivers/gpu/drm/tegra/drm.c @@ -960,7 +960,8 @@ int host1x_client_iommu_attach(struct host1x_client *client) * not the shared IOMMU domain, don't try to attach it to a different * domain. This allows using the IOMMU-backed DMA API. */ - if (domain && domain != tegra->domain) + if (domain && domain->type != IOMMU_DOMAIN_IDENTITY && + domain != tegra->domain) return 0; if (tegra->domain) {