Subject: [PATCH 10/14] PCI: tegra: Move PCIe driver to drivers/pci/host

From: [email-masked] (Andrew Murray)
Date: Thu, 17 Jan 2013 15:42:36 +0000

On Wed, Jan 16, 2013 at 06:31:01PM +0000, Thierry Reding wrote:
> Alright, putting the functions into pci_ops doesn't sound like a very
> good idea then. Or perhaps it would make sense for hardware where the
> root complex and the MSI controller are handled by the same driver.
> Basically it could be done as a shortcut and if those are not filled
> in, the drivers could still opt to look up an MSI controller from a
> phandle specified in DT.
> 
> Even another alternative would be to keep the functions within the
> struct pci_ops and use generic ones if an external MSI controller is
> used. Just tossing around ideas.

I think an ideal solution would be for additional logic in drivers/msi.c
(e.g. in functions like msi_capability_init) to determine (based on the
passed in pci_dev) which MSI controller ops to use. I'm not sure the best
way to implement an association between an MSI controller and PCI busses
(I believe arch/sparc does something like this - perhaps there will be
inspiration there).

As you've pointed out, most RCs will have their own MSI controllers - so
it should be easy to register and associate both together.

I've submitted my previous work on MSI controller registration, but it
doesn't quite solve this problem - perhaps it can be a starting point?

Andrew Murray