On Saturday 05 July 2014 14:25:52 Rob Herring wrote: > On Tue, Jul 1, 2014 at 1:43 PM, Liviu Dudau <Liviu.Dudau@xxxxxxx> wrote: > > The ranges property for a host bridge controller in DT describes > > the mapping between the PCI bus address and the CPU physical address. > > The resources framework however expects that the IO resources start > > at a pseudo "port" address 0 (zero) and have a maximum size of IO_SPACE_LIMIT. > > The conversion from pci ranges to resources failed to take that into account. > > I don't think this change is right. There are 2 resources: the PCI bus > addresses and cpu addresses. This function deals with the cpu > addresses. Returning pci addresses for i/o and cpu addresses for > memory is going to be error prone. We probably need both cpu and pci > resources exposed to host controllers. > > Making the new function only deal with i/o bus resources and naming it > of_pci_range_to_io_resource would be better. I think you are correct that this change by itself is will break existing drivers that rely on the current behavior of of_pci_range_to_resource, but there is also something wrong with the existing implementation: of_pci_range_to_resource() at the moment returns a the address in cpu address space (i.e. IORESOURCE_MEM) but sets the res->flags value to IORESOURCE_IO, which means it doesn't fit into the resource tree. Liviu's version gets that part right, and it would be nice to fix that eventually, however we do it here. Arnd -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
