[PATCH 24/32] pci: PCIe driver for Marvell Armada 370/XP systems

Jason Gunthorpe jgunthorpe at obsidianresearch.com
Wed Mar 13 13:02:05 EDT 2013


On Wed, Mar 13, 2013 at 09:18:15AM +0100, Thierry Reding wrote:

> Mitch already answered this. The specification is now almost 15 years
> old and it couldn't possibly have foreseen all of the future use-cases.
> If the specification is too restrictive and Mitch gives his blessing to
> remove some of the restrictions, I don't see any reason why we shouldn't
> do so if it lets us represent the reality of hardware more accurately in
> DT.

I understand the spec is old, and I have no problem with making a
Linux specific revision, but do *that* - don't bury some random
deviation inside the bindings for a driver. I even suggested some
language, but I feel more thought is needed to consider how to model
the standardized ECAM mechanism..

> Furthermore we're not discussing radical changes. None of the changes
> will be backwards-incompatible, but they will allow recent hardware to
> be represented more correctly or conveniently.

Sure, but it is still inconsistent, one MMIO config mechansim is in
ranges, one is in regs. Plus I don't think tegra's case is a great
starting point to design a spec update, it's config access mechanism
is especially strange...

Anyhow, I think this has been hashed to death, as long as your final
binding has the 'device_type = pci' on the pcie-controller node I
think it will be fine.

Jason



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