Re: [PATCH v4 05/16] iommu: Move bus setup to IOMMU device registration

[Jon Hunter]

Hi Robin,

On 15/08/2022 17:20, Robin Murphy wrote:
> Move the bus setup to iommu_device_register(). This should allow
> bus_iommu_probe() to be correctly replayed for multiple IOMMU instances,
> and leaves bus_set_iommu() as a glorified no-op to be cleaned up next.
>
> At this point we can also handle cleanup better than just rolling back
> the most-recently-touched bus upon failure - which may release devices
> owned by other already-registered instances, and still leave devices on
> other buses with dangling pointers to the failed instance. Now it's easy
> to clean up the exact footprint of a given instance, no more, no less.


Since this change, I have noticed that the DRM driver on Tegra20 is 
failing to probe and I am seeing ...

 tegra-gr2d 54140000.gr2d: failed to attach to domain: -19
 drm drm: failed to initialize 54140000.gr2d: -19

Bisect points to this change and reverting it fixes it. Let me know if 
you have any thoughts.

Cheers
Jon

--
nvpublic