Re: [PATCH v3 2/3] arm64: dts: Add APM X-Gene DMA device and DMA clock DTS nodes

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



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



[Index of Archives]     [Linux Kernel]     [Linux ARM (vger)]     [Linux ARM MSM]     [Linux Omap]     [Linux Arm]     [Linux Tegra]     [Fedora ARM]     [Linux for Samsung SOC]     [eCos]     [Linux PCI]     [Linux Fastboot]     [Gcc Help]     [Git]     [DCCP]     [IETF Announce]     [Security]     [Linux MIPS]     [Yosemite Campsites]

  Powered by Linux