Re: [PATCH] ath10k: Enable IOMMU support for WCN3990 target

[Kalle Valo <kvalo@codeaurora.org>]

Arnd Bergmann <arnd@arndb.de> writes:

> On Thu, Mar 1, 2018 at 2:18 PM, Govind Singh <govinds@qti.qualcomm.com> wrote:
>>>> The asm/dma-iommu.h header file exsists only on arm32, no other architecture.
>>>> I'm not sure about the purpose of the patch to start with:
>>>> it's normally up to the platform code to allocate IOMMU domains,
>>>> device drivers should only need to manually interact with the
>>>> IOMMU layer if they need more than one domain, but this ath10k
>>>> patch appears to be using the default domain and should have no
>>>> effect as long as the platform code works correctly.
>> Thanks Arnd, I have fixed this and migrated to 64bit
>> API's(iommu_attach_device/iommu_detach_device/
>> iommu_get_domain_for_dev), will share the next revision.
>> I tried using the default domain by adding the stream ID and mask in
>> dt and no manual interaction, but it is resulting in TZ error and
>> unhandled context fault.
>> Seems I need to provide explicit mapping range(aperture_start/
>> aperture_end) as this is only working combination for me..
>
> I don't see why you need to do that at all, can you clarify?
>
> The IOMMU should be set up implicitly for you here based on the iommus
> property in DT, with no driver changes at all. This should work on all
> architectures/

Maybe Govind is using some out-of-tree tree which is buggy in this
regard?

-- 
Kalle Valo