2 Oct
2020
2 Oct
'20
7:05 p.m.
On Thu, Oct 1, 2020 at 1:50 PM Marek Vasut marex@denx.de wrote:
In Linux, R-Car3 uses IOMMU, so there is no performance hit on that specific hardware. On iMX8M, you would likely need to set some bit which indicates the hardware supports only 32bit DMA, so the DMA buffers would be allocated below the 32bit barrier, also no big problem. I think it is one of the DMA flags, DMA_BIT_MASK(32) or so.
Just saw a recent discussion on this and the recommendation was to use the 'dma-ranges' property.
Please check: