Re: dma_mask limited to 32-bits with OF platform device

[Robin Murphy]

On 12/02/2020 12:33 pm, Roger Quadros wrote:
[...]
> For now, let's say that we limit dma-ranges to 4GB size. with 
> "dma-ranges = <0x00000000 0x00000000 0x1 0x00000000>;"
> Then, dma_bus_limit is set correctly to 0xffffffff, SATA driver sets 
> masks to 64-bit as IP supports that.
>
> [ÂÂ 13.306847] ahci 4a140000.sata: dma_mask 0xffffffffffffffff, 
> coherent_mask 0xffffffffffffffff, dma_bus_limit 0xffffffff
>
> However, the SATA controller still tries to do DMA above 32-bits.
> dma_alloc() doesn't seem to be taking dma_bus_limit into account?

Yay ARM LPAE... Peter and Christoph have already been playing 
whack-a-mole with other bugs under that config - is this with or without 
SWIOTLB? (and whichever way, does the other work any better?)

Robin.