Re: [PATCH] arch/tile: new multi-core architecture for Linux

[Arnd Bergmann <arnd@arndb.de>]

On Friday 28 May 2010, Chris Metcalf wrote:
> I looked at where inb() and friends are used, and although we can get
> close to not requiring them for tile, it's not quite there, and will
> need some further discussions on the various lists to clean up enough
> for our purposes.  There are three problems that surface when I try to
> remove the inb family:
> 
> 1. The ide-io-std.c file sets up the default_tp_ops, which we override
> in our IDE driver, but we still have to build this file, and it contains
> calls to inb, etc.

It's only needed in the IDE layer though and will go away once you
move to an ATA driver, right?

> 2. The usb pci quirks file contains some quirks that use inb and outb,
> and since we support PCI, we have to try to compile this file.
> 
> 3. CONFIG_DEVPORT defaults to yes, unless you're M68K.
>
> None of this seems to depend on CONFIG_HAS_IOPORT.

All three places you have found seem to be actual bugs.
 
> Our PCI driver supports IOMEM read/write, but not IOPORT.
> 
> Perhaps something like CONFIG_ARCH_PCI_HAS_NO_IOPORT or some such, and
> then we can disable all of the above things if that config option is
> present (and CONFIG_HAS_IOPORT is false also?).

That's what CONFIG_NO_IOPORT is supposed to be used for in the
first place, so I think we should just use the existing CONFIG_HAS_IOPORT
symbol to disable the broken code you found. CONFIG_DEVPORT then
not even needs to check for M68K.

	Arnd