Thanks, with regards, Ram On Mon, Jan 19, 2015 at 8:11 PM, Rameshwar Sahu <rsahu@xxxxxxx> wrote: > Hi Arnd, > > > > > > > Thanks, > with regards, > Ram > > On Mon, Jan 19, 2015 at 7:10 PM, Arnd Bergmann <arnd@xxxxxxxx> wrote: >> >> 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. > > > I referred this patch from AMD only. >> >> >> The value should be >> >> dma-ranges = <0x40 0x0 0x40 0x0 0x200 0>; > > > then it should be : > > dma-ranges = <0x40 0x0 0x40 0x0 0x400 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, > > > Do you mean all other device controller node in DT here?? > Basically these are all device controller memory, as what I understood is > dma-ranges tells about DDR ranges like start address of DDR > and length. > > >> >> 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 >> -- >> To unsubscribe from this list: send the line "unsubscribe dmaengine" in >> the body of a message to majordomo@xxxxxxxxxxxxxxx >> More majordomo info at http://vger.kernel.org/majordomo-info.html > > -- To unsubscribe from this list: send the line "unsubscribe dmaengine" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
