Re: [PATCH 0/5] mfd: replace IORESOURCE_IO by IORESOURCE_MEM

Russell King
2012-08-06T19:22:40Z

On Mon, Aug 06, 2012 at 04:58:06PM +0100, Mark Brown wrote:
> On Mon, Aug 06, 2012 at 11:56:47PM +0800, Haojian Zhuang wrote:
> > On Mon, Aug 6, 2012 at 11:46 PM, Mark Brown
>
> > > Right, but _MEM isn't terribly relevant either. If anything _IO is a
> > > bit better as ioports are *somewhat* similar to registers.
>
> > The problem is that each bit is already used in 32-bit IORESOURCE. I can't
> > find a empty bit to define the new IORESOURCE.
>
> That's one reason why I've not attacked this problem myself, but frankly
> I'm totally happy with using _IO here so I've not looked particularly
> closely.

NO. This is stupid. We've been here before, and I've said what I'm
saying below before too.

IORESOURCE_IO is for PCI/ISA IO resources.
IORESOURCE_MEM is for _memory mapped_ IO resources.

On ARM, we only have memory mapped IO resources, with the exception that
if we have a real PCI/ISA bus, we give them IORESOURCE_IO resources.

Never use IORESOURCE_IO for anything but PCI/ISA bus IO resources. Ever.

--
Russell King
Linux kernel 2.6 ARM Linux - http://www.arm.linux.org.uk/