Re: [PATCH] dra7: sata: Fix SATA with CONFIG_ARM_LPAE enabled

[Tony Lindgren <tony@atomide.com>]

* Roger Quadros <rogerq@ti.com> [200304 09:01]:
> Even though the TRM says that SATA IP has 36 address bits
> wired in the SoC, we see bus errors whenever any address
> greater than 32-bit is given to the controller.
> 
> This happens on dra7-EVM with 4G of RAM with CONFIG_ARM_LPAE=y.
> 
> As a workaround we limit the DMA address range to 32-bits
> for SATA.
> 
> Cc: Christoph Hellwig <hch@lst.de>
> Cc: Robin Murphy <robin.murphy@arm.com>
> Cc: Rob Herring <robh+dt@kernel.org>
> Reported-by: Yan Liu <yan-liu@ti.com>
> Signed-off-by: Roger Quadros <rogerq@ti.com>
> ---
> 
> NOTE: Currently ARM dma-mapping code doesn't account for devices
> bus_dma_limit. This is fixed in [1].
> 
> [1] https://lkml.org/lkml/2020/2/18/712

So is this dts patch safe to apply without the series above?

And should this dts patch be applied as a fix or can it wait
until the merge window?

Regards,

Tony

>  arch/arm/boot/dts/dra7.dtsi | 25 ++++++++++++++++---------
>  1 file changed, 16 insertions(+), 9 deletions(-)
> 
> diff --git a/arch/arm/boot/dts/dra7.dtsi b/arch/arm/boot/dts/dra7.dtsi
> index d78b684e7fca..895462c22d1c 100644
> --- a/arch/arm/boot/dts/dra7.dtsi
> +++ b/arch/arm/boot/dts/dra7.dtsi
> @@ -642,15 +642,22 @@
>  		};
>  
>  		/* OCP2SCP3 */
> -		sata: sata@4a141100 {
> -			compatible = "snps,dwc-ahci";
> -			reg = <0x4a140000 0x1100>, <0x4a141100 0x7>;
> -			interrupts = <GIC_SPI 49 IRQ_TYPE_LEVEL_HIGH>;
> -			phys = <&sata_phy>;
> -			phy-names = "sata-phy";
> -			clocks = <&l3init_clkctrl DRA7_L3INIT_SATA_CLKCTRL 8>;
> -			ti,hwmods = "sata";
> -			ports-implemented = <0x1>;
> +		sata_aux_bus {
> +			#address-cells = <1>;
> +			#size-cells = <2>;
> +			compatible = "simple-bus";
> +			ranges = <0x0 0x4a140000 0x0 0x1200>;
> +			dma-ranges = <0x0 0x0 0x1 0x00000000>;
> +			sata: sata@4a141100 {
> +				compatible = "snps,dwc-ahci";
> +				reg = <0x0 0x0 0x1100>, <0x1100 0x0 0x7>;
> +				interrupts = <GIC_SPI 49 IRQ_TYPE_LEVEL_HIGH>;
> +				phys = <&sata_phy>;
> +				phy-names = "sata-phy";
> +				clocks = <&l3init_clkctrl DRA7_L3INIT_SATA_CLKCTRL 8>;
> +				ti,hwmods = "sata";
> +				ports-implemented = <0x1>;
> +			};
>  		};
>  
>  		/* OCP2SCP1 */
> -- 
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