Re: [PATCH] iommu: Ensure .iotlb_sync is called correctly

Jason Gunthorpe
2026-04-08T16:28:53Z

On Wed, Apr 08, 2026 at 03:40:57PM +0100, Robin Murphy wrote:
> Many drivers have no reason to use the iotlb_gather mechanism, but do
> still depend on .iotlb_sync being called to properly complete an unmap.
> Since the core code is now relying on the gather to detect when there
> is legitimately something to sync, it should also take care of encoding
> a successful unmap when the driver does not touch the gather itself.
>
> Fixes: 90c5def10bea ("iommu: Do not call drivers for empty gathers")
> Reported-by: Jon Hunter <jonathanh@nvidia.com>
> Closes: https://lore.kernel.org/r/8800a38b-8515-4bbe-af15-0dae81274bf7@nvidia.com
> Signed-off-by: Robin Murphy <robin.murphy@arm.com>
> ---
> drivers/iommu/iommu.c | 6 ++++++
> 1 file changed, 6 insertions(+)

Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>

Jason