Messages in this thread | | | From | Arnd Bergmann <> | Subject | Re: [PATCH v3 2/3] arm64: dts: Add APM X-Gene DMA device and DMA clock DTS nodes | Date | Mon, 19 Jan 2015 14:40:36 +0100 |
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On Monday 19 January 2015 18:11:08 Rameshwar Prasad Sahu wrote: > diff --git a/arch/arm64/boot/dts/apm/apm-storm.dtsi b/arch/arm64/boot/dts/apm/apm-storm.dtsi > index f1ad9c2..e20da23 100644 > --- a/arch/arm64/boot/dts/apm/apm-storm.dtsi > +++ b/arch/arm64/boot/dts/apm/apm-storm.dtsi > @@ -103,6 +103,9 @@ > #size-cells = <2>; > ranges; > > + /* DDR range is 42-bit addressing */ > + dma-ranges = <0x40 0x0 0x40 0x0 0x1ff 0xffffffff>; > + >
The comment above is misleading, and the value is wrong. I assume you copied these from the AMD patch that introduced the respective property.
The value should be
dma-ranges = <0x40 0x0 0x40 0x0 0x200 0>;
to say that any DMA to physical addresses from 0 to 0x3f.ffffffff is disallowed and dma to physical addresses from 0x40.00000000 to 0x23f.ffffffff is allowed and gets translated using an identity mapping.
I also see that on Mustang, all memory is outside of this range, which is a bit suspicious, while your PCI memory space is included.
It would be best to match the numbers up with your data sheet.
Arnd
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