...
> static int tegra_smmu_attach_dev(struct iommu_domain *domain,
> struct device *dev)
> {
> + struct iommu_fwspec *fwspec = dev_iommu_fwspec_get(dev);
> struct tegra_smmu *smmu = dev_iommu_priv_get(dev);
> struct tegra_smmu_as *as = to_smmu_as(domain);
> - struct device_node *np = dev->of_node;
> - struct of_phandle_args args;
> unsigned int index = 0;
> int err = 0;
>
> - while (!of_parse_phandle_with_args(np, "iommus", "#iommu-cells", index,
> - &args)) {
> - unsigned int swgroup = args.args[0];
> -
> - if (args.np != smmu->dev->of_node) {
> - of_node_put(args.np);
> - continue;
> - }
> -
> - of_node_put(args.np);
> + if (!fwspec || fwspec->ops != &tegra_smmu_ops)
> + return -ENOENT;
In previous reply you said that these fwspec checks are borrowed from
the arm-smmu driver, but I'm now looking at what other drivers do and I
don't see them having this check.
Hence I'm objecting the need to have this check here. You either should
give a rational to having the check or it should be removed.
Please never blindly copy foreign code, you should always double-check it.
