Re: [PATCH 1/2] arm64: dts: imx8mm: specify dma-ranges

Adam Ford
2021-05-05T11:38:10Z

On Tue, May 4, 2021 at 3:21 AM Lucas Stach <l.stach@pengutronix.de> wrote:
>
> DMA addressing capabilities on i.MX8MM are limited by the interconnect,
> same as on i.MX8MQ. Add dma-ranges to the the peripheral bus to let
> the kernel know about this.

Can you point me to the section of the reference manual where this is
found? I'm guessing a similar thing would be applicable to the 8M
Nano as well, but I want to understand first.

thanks

adam
>
> Signed-off-by: Lucas Stach <l.stach@pengutronix.de>
> ---
> arch/arm64/boot/dts/freescale/imx8mm.dtsi | 1 +
> 1 file changed, 1 insertion(+)
>
> diff --git a/arch/arm64/boot/dts/freescale/imx8mm.dtsi b/arch/arm64/boot/dts/freescale/imx8mm.dtsi
> index 6bf1d15ba16a..5bdc730f6132 100644
> --- a/arch/arm64/boot/dts/freescale/imx8mm.dtsi
> +++ b/arch/arm64/boot/dts/freescale/imx8mm.dtsi
> @@ -261,6 +261,7 @@ soc@0 {
> #address-cells = <1>;
> #size-cells = <1>;
> ranges = <0x0 0x0 0x0 0x3e000000>;
> + dma-ranges = <0x40000000 0x0 0x40000000 0xc0000000>;
> nvmem-cells = <&imx8mm_uid>;
> nvmem-cell-names = "soc_unique_id";
>
> --
> 2.29.2
>
>
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