30.09.2020 08:41, Nicolin Chen пишет:
> On Wed, Sep 30, 2020 at 08:39:54AM +0300, Dmitry Osipenko wrote:
>> 30.09.2020 03:30, Nicolin Chen пишет:
>>> 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;
>>
>> s/&tegra_smmu_ops/smmu->iommu.ops/
>>
>> Secondly, is it even possible that fwspec could be NULL here or that
>> fwspec->ops != smmu->ops?
>
> I am following what's in the arm-smmu driver, as I think it'd be
> a common practice to do such a check in such a way.
>
Please check whether it's really needed. It looks like it was needed
sometime ago, but that's not true anymore.
