Hi Rob, On 01/03/2021 07:45, Irui Wang wrote: > On Wed, 2021-02-10 at 16:53 -0600, Rob Herring wrote: >> On Wed, Feb 03, 2021 at 04:37:48PM +0800, Irui Wang wrote: >>> Adds dma-ranges property for DMA addresses translation. >>> >>> Signed-off-by: Irui Wang <irui.wang@xxxxxxxxxxxx> >>> --- >>> Documentation/devicetree/bindings/media/mediatek-vcodec.txt | 2 ++ >>> 1 file changed, 2 insertions(+) >>> >>> diff --git a/Documentation/devicetree/bindings/media/mediatek-vcodec.txt b/Documentation/devicetree/bindings/media/mediatek-vcodec.txt >>> index f85276e629bf..e4644f8caee9 100644 >>> --- a/Documentation/devicetree/bindings/media/mediatek-vcodec.txt >>> +++ b/Documentation/devicetree/bindings/media/mediatek-vcodec.txt >>> @@ -23,6 +23,8 @@ Required properties: >>> - iommus : should point to the respective IOMMU block with master port as >>> argument, see Documentation/devicetree/bindings/iommu/mediatek,iommu.txt >>> for details. >>> +- dma-ranges : describes how the physical address space of the IOMMU maps >>> + to memory. >> >> dma-ranges is supposed to be in a bus/parent node. > Dear Rob, > > The mt8192 iommu support 0~16GB iova. We separate it to four banks: > 0~4G; 4G~8G; 8G~12G; 12G~16G. > > The "dma-ranges" could be used to adjust the bank we locate. > If we don't set this property. The default range always is 0~4G. > > Here we don't have actual bus/parent concept here. And the iova > requirement is for our HW. Thus put the property in our node. > > Is this OK? If this is ok for you, I will put this message in the commit > message and binding in next version. Can you answer Irui's question? Just a reminder... Much appreciated! Regards, Hans > > Regards >> >>> One of the two following nodes: >>> - mediatek,vpu : the node of the video processor unit, if using VPU. >>> - mediatek,scp : the node of the SCP unit, if using SCP. >>> -- >>> 2.25.1 >>> >
