Re: [PATCH v3 1/5] dt-bindings: dmaengine: Add SpacemiT K3 DMA compatible string

Krzysztof Kozlowski
2026-04-01T06:42:34Z

On Tue, Mar 31, 2026 at 04:27:04PM +0800, Troy Mitchell wrote:
> From: Guodong Xu <guodong@riscstar.com>
>
> Add the "spacemit,k3-pdma" compatible string for the SpacemiT K3 SoC.
>
> While the K3 PDMA IP reuses most of the design found on the earlier K1 SoC,
> a new compatible string is required due to the following hardware differences:

Please wrap commit message according to Linux coding style / submission
process (neither too early nor over the limit):
https://elixir.bootlin.com/linux/v6.4-rc1/source/Documentation/process/submitting-patches.rst#L597

>
> - Variable extended DRCMR base: The DRCMR (DMA Request/Command Register) base
> address for extended DMA request numbers (>= 64) differs from the K1
> implementation, requiring different driver ops.

Please do not mention drivers.

> - Memory addressing capabilities: Unlike the K1 SoC, which had memory addressing
> limitations (e.g., restricted to the 0-4GB space) and required a dedicated
> dma-bus with dma-ranges to restrict memory allocations, the K3 DMA masters
> possess full memory addressing capabilities.

Programming interface is still compatible, regardless of memory
addressing limitations, so that is rather incorrect reason.

Best regards,
Krzysztof