Arnd, Going through this a couple questions came out...
On Tue, Jun 18, 2013 at 11:35:50PM +0200, Arnd Bergmann wrote: > On Tuesday 18 June 2013, Ezequiel Garcia wrote: > > + > > + ranges = > > + <0x82000000 0 0x40000 0xffff0001 0x40000 > > 0 0x00002000 > > + 0x82000000 0 0x80000 0xffff0001 0x80000 > > 0 0x00002000 > > + 0x82000000 0 0xe0000000 0xffff0002 0 > > 0 0x08000000 > > + 0x81000000 0 0 0xffff0002 > > 0x8000000 0 0x00100000>; > > As pointed out on IRC, this is not a good representation of the memory space, > since it requires a non-zero sys->mem_offset, and it conflicts with the > straight > mapping I suggested. > > I think it should be > > 0x82000000 0 0xe0000000 0xffff0002 0 > 0xe0000000 0x08000000 So far, so good. > > if we want to encode the aperture in the ranges property here, i.e. have > a 1:1 mapping between PCI memory space and MBUS space, and in mbus, > you need the corresponding > > - 0xffff0002 0 0xe0000000 0x8100000 > + 0xffff0002 0xe0000000 0xe0000000 0x8100000 ... I obviously got something wrong, but I thought you said that this change allowed to *not* have any mbus-node ranges translation. > > so that mbus actually translates the right addresses. You could also > have the PCI memory space start at 0, which would mean > > 0x82000000 0 0 0xffff0002 0 0 0x08000000 > > and > > 0xffff0002 0 0xe0000000 0x8100000 Mmm.. and why is this option acceptable? > > Note that the driver doesn't actually handle the generic case correctly, you > would > need to apply this patch > This patch does not apply. I tried to understand what you did, but I'm confused by the fact I don't need to apply any patch to make it work on my boxes, using your proposed ranges translations. > diff --git a/drivers/pci/host/pci-mvebu.c b/drivers/pci/host/pci-mvebu.c > index 13a633b..aa674f4 100644 > --- a/drivers/pci/host/pci-mvebu.c > +++ b/drivers/pci/host/pci-mvebu.c > @@ -790,6 +790,7 @@ static int __init mvebu_pcie_probe(struct platform_device > *pdev) > } > if (restype == IORESOURCE_MEM) { > of_pci_range_to_resource(&range, np, &pcie->mem); > + sys->mem_offset = range.cpu_addr - range.pci_addr; > pcie->mem.name = "MEM"; > } > } > > to deal with the generic case where the bus address is different from the > CPU address. > Thanks! -- Ezequiel GarcĂa, Free Electrons Embedded Linux, Kernel and Android Engineering http://free-electrons.com _______________________________________________ devicetree-discuss mailing list devicetree-discuss@lists.ozlabs.org https://lists.ozlabs.org/listinfo/devicetree-discuss