[PATCH v10 08/10] OF: PCI: Add support for parsing PCI host bridge resources from DT

[Lorenzo Pieralisi]

On Wed, Sep 10, 2014 at 05:53:47PM +0100, Liviu Dudau wrote:

[...]

> > > > > > > +		if (resource_type(res) == IORESOURCE_IO) {
> > > > > > > +			if (*io_base)
> > > > > > 
> > > > > > You do not zero io_base in the first place so you should ask the API
> > > > > > user to do that. Is 0 a valid value BTW ? If it is you've got to resort
> > > > > > to something else to detect multiple IO resources.
> > > 
> > > No, zero is not a valid value. It is the cpu_addr value from the IO range, I'm
> > > hopying that no one is crazy enough to map PCI address space at CPU address zero.
> > > Thanks for spotting the lack of initialisation though, I need to fix it.
> > 
> > Mmm...wasn't a trick question sorry :D
> > 
> > PCI host bridge /pci ranges:
> >    IO 0x00000000..0x0000ffff -> 0x00000000
> >    More than one I/O resource converted. CPU offset for old range lost!
> >      MEM 0x41000000..0x7fffffff -> 0x41000000
> >      pci-host-generic 40000000.pci: PCI host bridge to bus 0000:00
> >      pci_bus 0000:00: root bus resource [bu-01]
> >      pci_bus 0000:00: root bus resource [io  0x0000-0xffff]
> >      pci_bus 0000:00: root bus resource [mem 0x41000000-0x7fffffff]
> > 
> 
> Your DT puts the IO space at CPU address zero? Could you copy the relevant
> host bridge node from DT here?

It is kvmtools generated dts, may not be representative of real HW but
that's what it is. For the whole story:

http://comments.gmane.org/gmane.linux.kernel.pci/29199

Lorenzo