Re: [PATCH v3 1/7] dt-bindings: interconnect: Add a dma interconnect name

[Georgi Djakov <georgi.djakov@linaro.org>]

Hi Maxime,

On 2/11/19 17:02, Maxime Ripard wrote:
> The current DT bindings assume that the DMA will be performed by the
> devices through their parent DT node, and rely on that assumption for the
> address translation using dma-ranges.
> 
> However, some SoCs have devices that will perform DMA through another bus,
> with separate address translation rules. We therefore need to express that
> relationship, through the special interconnect name "dma".
> 
> Signed-off-by: Maxime Ripard <maxime.ripard@bootlin.com>
> ---
>  Documentation/devicetree/bindings/interconnect/interconnect.txt | 3 +++
>  1 file changed, 3 insertions(+)
> 
> diff --git a/Documentation/devicetree/bindings/interconnect/interconnect.txt b/Documentation/devicetree/bindings/interconnect/interconnect.txt
> index 5a3c575b387a..e69fc2d992c3 100644
> --- a/Documentation/devicetree/bindings/interconnect/interconnect.txt
> +++ b/Documentation/devicetree/bindings/interconnect/interconnect.txt
> @@ -51,6 +51,9 @@ interconnect-names : List of interconnect path name strings sorted in the same
>  		     interconnect-names to match interconnect paths with interconnect
>  		     specifier pairs.
>  
> +                     Reserved interconnect names:
> +                         * dma: Path from the device to the main memory of the system

Bikeshed: As it's from the device to the main memory, maybe here we can
also denote this my calling the path dma-mem or dma-memory. For other
paths, we are trying to mention both the source and the destination and
maybe it would be good to be consistent although this is special one.

Thanks,
Georgi