Re: [PATCH v5 11/18] iommu: exynos: remove useless device_add/remove callbacks

[Marek Szyprowski <m.szyprowski-Sze3O3UU22JBDgjK7y7TUQ@public.gmane.org>]

Hello,

On 2015-01-26 12:00, Joerg Roedel wrote:
> Hi Laurent,
>
> On Sun, Jan 25, 2015 at 05:38:22PM +0200, Laurent Pinchart wrote:
>> IOMMU groups still seem a bit unclear to me. Will Deacon has nicely explained
>> what they represent in
>> http://lists.infradead.org/pipermail/linux-arm-kernel/2014-December/310816.html.
>> The IOMMU core doesn't make groups
>> mandatory, but requires them in some code paths.
>>
>> For example the coldplug device add function add_iommu_group() called for all
>> devices already registered when bus_set_iommu() is called will try to warn of
>> devices added multiple times with a WARN_ON(dev->iommu_group). Another example
>> is the iommu_bus_notifier() function which will call the remove_device()
>> operation only when dev->iommu_group isn't NULL.
>>
>> I'm thus unsure whether groups should be made mandatory, or whether the IOMMU
>> core should be fixed to make them really optional (or, third option, whether
>> there's something I haven't understood properly).
> My plan is to make IOMMU groups mandatory. I am currently preparing and
> RFC patch-set to introduce default-domains (which will be per group). So
> when all IOMMU drivers are converted to make use of default domains the
> iommu groups will be mandatory.

Thanks for the comment, I will implement all that will be needed for it 
to exynos
iommu driver, but I would like to ask if you plan to merge my existing 
patches for
exynos iommu driver to your tree?

Best regards
-- 
Marek Szyprowski, PhD
Samsung R&D Institute Poland