iommu/tegra-smmu: Make tegra_smmu_probe_device() to handle all IOMMU phandles

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>
Link: https://lore.kernel.org/r/20210312155439.18477-1-digetx@gmail.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>

diff --git a/drivers/iommu/tegra-smmu.c b/drivers/iommu/tegra-smmu.c
index 97eb62f667d22d18b45cabeee90231e7aada3339..602aab98c0794812f94c30c6b7b54f29cddf9ec0 100644 (file)
--- a/drivers/iommu/tegra-smmu.c
+++ b/drivers/iommu/tegra-smmu.c
@@ -849,12 +849,11 @@ static struct iommu_device *tegra_smmu_probe_device(struct device *dev)
                smmu = tegra_smmu_find(args.np);
                if (smmu) {
                        err = tegra_smmu_configure(smmu, dev, &args);
-                       of_node_put(args.np);
 
-                       if (err < 0)
+                       if (err < 0) {
+                               of_node_put(args.np);
                                return ERR_PTR(err);
-
-                       break;
+                       }
                }
 
                of_node_put(args.np);