Re: [PATCH 6/6] ARM: dts: Add pcie controller node for Samsung EXYNOS5440 SoC

From: Arnd Bergmann
Date: Wed Jun 12 2013 - 11:11:17 EST


On Tuesday 11 June 2013, Jingoo Han wrote:
> > > + ranges = <0x00000800 0 0x40000000 0x40000000 0 0x00200000 /* configuration space */
> > > + 0x81000000 0 0 0x40200000 0 0x00004000 /* downstream I/O */
> > > + 0x82000000 0 0 0x40204000 0 0x10000000>; /* non-prefetchable memory */
> > > + };
> >
> ...
> > Also, shouldn't your memory space end on a 256MB boundary, rather than
> > extend up to 0x50203fff?
>
> According to the manual of Exynos PCIe, each memory space for Exynos PCIe
> can support 512MB, including I/O, CFG regions.
>
> Is there any problem when over 256MB boundary is used?
> Please let me know. :)

No, that's not a problem, but I think you should have the window span
the entire space that is provided in hardware. If there are 512 MB total, why
not use them?

You could use

ranges = <0x82000000 0 0 0x40204000 0 0x1fdfc000>;

to pass a range for the memory space that extends all the way until
0x5fffffff.

Arnd
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