Re: [PATCH v2] iommu/exynos: Fix set_platform_dma_ops() callback

[Jason Gunthorpe <jgg@ziepe.ca>]

On Thu, Mar 16, 2023 at 12:25:14AM +0100, Marek Szyprowski wrote:
> There are some subtle differences between release_device() and
> set_platform_dma_ops() callbacks, so separate those two callbacks. Device
> links should be removed only in release_device(), because they were
> created in probe_device() on purpose and they are needed for proper
> Exynos IOMMU driver operation. While fixing this, remove the conditional
> code as it is not really needed.
> 
> Reported-by: Jason Gunthorpe <jgg@ziepe.ca>
> Fixes: 189d496b48b1 ("iommu/exynos: Add missing set_platform_dma_ops callback")
> Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
> ---
> v2:
> - keep set_platform_dma_ops only on ARM 32bit
> 
> Some more background why set_platform_dma_ops is needed on ARM 32bit is
> available here:
> https://lore.kernel.org/all/9a12fcac-c347-5d81-acef-1124c50d0c37@arm.com/
> ---
>  drivers/iommu/exynos-iommu.c | 17 ++++++++++-------
>  1 file changed, 10 insertions(+), 7 deletions(-)

It seems OK, but do you know what state the device is left in after
exynos_iommu_detach_device ? Ie is it blocking or identity?

Jason