Re: [PATCH v5 4/6] drm/sprd: add Unisoc's drm display controller driver

[Robin Murphy]

On 2021-05-17 10:27, Joerg Roedel wrote:
> On Fri, Apr 30, 2021 at 08:20:10PM +0800, Kevin Tang wrote:
> > Cc  Robin & Joerg
>
> This is just some GPU internal MMU being used here, it seems. It doesn't
> use the IOMMU core code, so no Ack needed from the IOMMU side.

Except the actual MMU being used is drivers/iommu/sprd_iommu.c - this is 
just the display driver poking directly at the interrupt registers of 
its associated IOMMU instance. I still think this is wrong, and that it 
should be treated as a shared interrupt, with the IOMMU driver handling 
its own registers and reporting to the client through the standard 
report_iommu_fault() API, especially since there are apparently more 
blocks using these IOMMU instances than just the display.

Robin.