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

Frieder Schrempf
2021-05-04T09:07:26Z

On 04.05.21 10:20, Lucas Stach 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.
>
> Signed-off-by: Lucas Stach <l.stach@pengutronix.de>

Reviewed-by: Frieder Schrempf <frieder.schrempf@kontron.de>
Tested-by: Frieder Schrempf <frieder.schrempf@kontron.de>

With this applied the following errors don't occur anymore when using
the GPU with a board that has 4GB of RAM.

etnaviv-gpu 38000000.gpu: AXI bus error
etnaviv-gpu 38000000.gpu: MMU fault status 0x00000000
etnaviv-gpu 38000000.gpu: recover hung GPU!

> ---
> 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";