Re: dma-coherent property for PCIe Root

[Jon Masters]

On 9/14/20 1:23 AM, Valmiki wrote:
> Hi All,
>
> How does "dma-coherent" property will work for PCIe as RC on an
> ARM SOC ?
> Because the end point device drivers are the one which will request dma 
> buffers and Root port driver doesn't involve in data path of end point
> except for handling interrupts.
>
> How does EP DMA buffers will be hardware coherent if RC driver exposes
> dma-coherent property ?

This simply means that the RC supports maintaining coherency, it doesn't 
mean that the RC driver does anything. It's a property of the hardware.

Jon.

--
Computer Architect