[PATCH 07/15] ARM: dove: use fixed PCI i/o mapping

[Arnd Bergmann]

On Monday 09 July 2012, Nicolas Pitre wrote:
> On Mon, 9 Jul 2012, Rob Herring wrote:
> 
> > Why use 1M when 64K is enough based on our prior conversations? The more
> > we standardize the configuration, the more we can make common. I think
> > the majority of the pci setup functions can be consolidated. It's really
> > just data differences for the resource setup. I only used 1M alignment
> > in case there were some alignment requirements in the h/w and it can't
> > handle a starting pci bus address of 0x10000. I think it's just the
> > Marvell parts that do this, so if anyone knowledgeable on those parts
> > can comment it would help.
> 
> The only Marvell board I have which can accommodate a PCI card does 
> support 3.3V PCI cards only.  Otherwise this is all PCI Express.  And 
> the only PCI cards with I/O space I've seen are 5V PCI cards.

All graphics cards and ATA controllers support backwards compatible PIO
access to the VGA or IDE registers, and they are available for PCI express.
A lot of PCIe legacy I/O cards (uart, printer, 	GPIO) can also use PIO
mode to be backwards compatible.

> So I'd say: go for the option with the best consolidation outcome.  No 
> one is using cards with I/O space on those platforms.

That is probably true.

	Arnd