Re: [PATCH 1/9] iommu/of: Drop early initialisation hooks

[JeffyChen <jeffy.chen-TNX95d0MmH7DzftRWevZcw@public.gmane.org>]

Hi Marek,

Thanks for your reply.

On 01/11/2018 05:40 PM, Marek Szyprowski wrote:
> Hi Jeffy,
>
> On 2018-01-11 09:22, Jeffy Chen wrote:
>> With the probe-deferral mechanism, early initialisation hooks are no
>> longer needed.
>>
>> Suggested-by: Robin Murphy <robin.murphy-5wv7dgnIgG8@public.gmane.org>
>> Signed-off-by: Jeffy Chen <jeffy.chen-TNX95d0MmH7DzftRWevZcw@public.gmane.org>
>> ---
>>
>>   drivers/iommu/arm-smmu-v3.c  |  2 +-
>>   drivers/iommu/arm-smmu.c     | 12 ++++++------
>>   drivers/iommu/exynos-iommu.c |  2 +-
>
> For Exynos IOMMU:
> Acked-by: Marek Szyprowski <m.szyprowski-Sze3O3UU22JBDgjK7y7TUQ@public.gmane.org>
>
> IPMMU and MSM IOMMU are no longer multi-platform safe after this patch.
> It breaks them in the same way as my commit 928055a01b3f ("iommu/exynos:
> Remove custom platform device registration code") broke Exynos IOMMU.
>
> You need a similar fix for them:
> https://www.spinics.net/lists/arm-kernel/msg627648.html

hmmm, right, i did saw this fix in the rockchip iommu driver too.

and there're also some other iommu drivers put bus_set_iommu in their 
probe() to avoid that.

maybe we can do it in the iommu framework?

for example:
1/ add a bus type member to struct iommu_device
2/ and a iommu_device_set_bus()
3/ do the bus_set_iommu stuff in iommu_device_register()
4/ undo bus_set_iommu in iommu_device_unregister()