On 2021-05-17 10:27, Joerg Roedel wrote:

On Fri, Apr 30, 2021 at 08:20:10PM +0800, Kevin Tang wrote:

quoted

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.