[PATCH v3 2/5] iommu: Resolve fwspec ops automatically

[Will Deacon]

On Fri, Jul 12, 2024 at 04:24:48PM +0100, Jon Hunter wrote:
> 
> On 12/07/2024 12:48, Robin Murphy wrote:
> 
> ...
> 
> > > I am seeing some failures on -next with some of our devices. Bisect
> > > is pointing to this commit. Looks like the host1x device is no
> > > longer probing successfully. I see the following ...
> > > 
> > >   tegra-host1x 50000000.host1x: failed to initialize fwspec: -517
> > >   nouveau 57000000.gpu: failed to initialize fwspec: -517
> > > 
> > > The probe seems to be deferred forever. The above is seen on
> > > Tegra210 but Tegra30 and Tegra194 are also having the same problem.
> > > Interestingly it is not all devices and so make me wonder if we are
> > > missing something on these devices? Let me know if you have any
> > > thoughts.
> > 
> > Ugh, tegra-smmu has been doing a complete nonsense this whole time - on
> > closer inspection, it's passing the fwnode of the *client device* where
> > it should be that of the IOMMU device :(
> > 
> > I *think* it should probably just be a case of:
> > 
> > -    err = iommu_fwspec_init(dev, of_fwnode_handle(dev->of_node));
> > +    err = iommu_fwspec_init(dev, of_fwnode_handle(smmu->dev->of_node));
> > 
> > since smmu->dev appears to be the same one initially passed to
> > iommu_device_register(), so it at least ought to match and work, but the
> > SMMU device vs. MC device thing leaves me mildly wary of how correct it
> > might be overall.
> > 
> > (Also now I'm wondering why I didn't just use dev_fwnode() there...)
> 
> 
> Yes making that change in the tegra-smmu driver does fix it.

Fantastic! I'll pick it up right now.

Cheers,

Will