Re: [PATCH v1 03/18] arm64: dts: imx8mq-evk: add reserve memory node for CMA region

Ezequiel Garcia
2021-02-17T19:40:54Z

Hi Benjamin,

On Wed, 2021-02-17 at 09:02 +0100, Benjamin Gaignard wrote:
> Define allocation range for the default CMA region.
>
> Signed-off-by: Benjamin Gaignard <benjamin.gaignard@collabora.com>
> Signed-off-by: Ezequiel Garcia <ezequiel@collabora.com>

Despite it seems like I signed-off this one...

> Signed-off-by: Adrian Ratiu <adrian.ratiu@collabora.com>
> ---
>  arch/arm64/boot/dts/freescale/imx8mq-evk.dts | 15 +++++++++++++++
>  1 file changed, 15 insertions(+)
>
> diff --git a/arch/arm64/boot/dts/freescale/imx8mq-evk.dts b/arch/arm64/boot/dts/freescale/imx8mq-evk.dts
> index 85b045253a0e..047dfd4a1ffd 100644
> --- a/arch/arm64/boot/dts/freescale/imx8mq-evk.dts
> +++ b/arch/arm64/boot/dts/freescale/imx8mq-evk.dts
> @@ -21,6 +21,21 @@ memory@40000000 {
>                 reg = <0x00000000 0x40000000 0 0xc0000000>;
>         };
>
>
> +       resmem: reserved-memory {
> +               #address-cells = <2>;
> +               #size-cells = <2>;
> +               ranges;
> +
> +               /* global autoconfigured region for contiguous allocations */
> +               linux,cma {
> +                       compatible = "shared-dma-pool";
> +                       reusable;
> +                       size = <0 0x3c000000>;
> +                       alloc-ranges = <0 0x40000000 0 0x40000000>;
> +                       linux,cma-default;
> +               };

... I'm not a fan of the change :)

Hopefully someone from NXP can provide some insight here?

If it's absolutely needed for the VPU, then I guess it should
be 1) very well documented and 2) moved to the top-lovel dtsi.

But if we can drop it, that'd be nicer.

Thanks,
Ezequiel