Re: [PATCH 1/2] pci: Add IORESOURCE_BIT entry for PCIe ECAM resources.

Grant Likely
2014-06-02T16:23:14Z

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On Mon, 2 Jun 2014 10:40:30 -0500, Kumar Gala <galak@codeaurora.org> wrote:
>
> On Jun 2, 2014, at 10:09 AM, Grant Likely <grant.likely@linaro.org> wrote:
>
> > On Sat, 31 May 2014 20:41:04 +0200, Arnd Bergmann <arnd@arndb.de> wrote:
> >> On Saturday 31 May 2014 01:36:40 Liviu Dudau wrote:
> >>> We would like to be able to describe PCIe ECAM resources as
> >>> IORESOURCE_MEM blocks while distinguish them from standard
> >>> memory resources. Add an IORESOURCE_BIT entry for this case.
> >>>
> >>> Signed-off-by: Liviu Dudau <Liviu.Dudau@arm.com>
> >>
> >> I still don't see any value in this at all. What is the advantage
> >> of doing this opposed to just having a standardized 'reg' property
> >> for a particular compatible string?
> >
> > I'm inclined to agree. It doesn't seem appropriate to put config space
> > in ranges, and the host controller binding is responsible for
> > identifying how config space is memory mapped.
> >
> > g.
>
> I don’t agree when it comes to ECAM, but we can drop this for now
> until someone really does that.

Okay, humor me then. What would a ranges property look like for ECAM? Do
you have an example? I believe there would need to be a separate entry
for each and every PCI device on the bus to get the config spaces to be
contiguous.

> However, what do we do with the 2 cases that exist in upstream that
> are using ranges for cfg space?

Ignore them in the core code? Make the specific host controller handle
them I would think.

g.