xen/grant-dma-iommu: Implement a dummy probe_device() callback

Update stub IOMMU driver (which main purpose is to reuse generic
IOMMU device-tree bindings by Xen grant DMA-mapping layer on Arm)
according to the recent changes done in the following
commit 57365a04c921 ("iommu: Move bus setup to IOMMU device registration").

With probe_device() callback being called during IOMMU device registration,
the uninitialized callback just leads to the "kernel NULL pointer
dereference" issue during boot. Fix that by adding a dummy callback.

Looks like the release_device() callback is not mandatory to be
implemented as IOMMU framework makes sure that callback is initialized
before dereferencing.

Reported-by: Viresh Kumar <[email protected]>
Fixes: 57365a04c921 ("iommu: Move bus setup to IOMMU device registration")
Signed-off-by: Oleksandr Tyshchenko <[email protected]>
Tested-by: Viresh Kumar <[email protected]>
Reviewed-by: Stefano Stabellini <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Juergen Gross <[email protected]>

0 files changed, 0 insertions, 0 deletions