[PATCH v3 03/12] bus: mvebu-mbus: Add static window allocation to the DT binding
Thomas Petazzoni
thomas.petazzoni at free-electrons.com
Wed Jun 19 03:12:55 EST 2013
Dear Arnd Bergmann,
On Tue, 18 Jun 2013 18:14:33 +0200, Arnd Bergmann wrote:
> Using 0xffff0002 as a placeholder for the pcie translation is definitely
> better than 0xffff0000 as you had before, but let me ask again in case
> you missed it the last time (and sorry if I missed the answer):
>
> Why not just put the actual translation here the way it happens for each
> of the PCIe ports? With the definition here, the PCIe driver actually has no
> way to figure out what settings the windows need to use!
Come on Arnd, this is something we have already discussed *countless*
times with you.
We *cannot* define translations for each PCIe port because we don't
know in advance how much I/O and memory space each PCIe device will
request. This is the reason why we have *one* global range for I/O
space and *one* global space for memory space, that are given to the
Linux PCI core, which then dynamically assigns sub-ranges for each
PCIe device into those two global ranges.
Best regards,
Thomas
--
Thomas Petazzoni, Free Electrons
Kernel, drivers, real-time and embedded Linux
development, consulting, training and support.
http://free-electrons.com
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