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    SubjectRe: [PATCH 1/2] of_pci_irq: add a check to fallback to standard device tree parsing
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    On Tue, 2018-02-06 at 15:50 +1100, Benjamin Herrenschmidt wrote:
    > On Tue, 2018-02-06 at 12:31 +0800, Ryder Lee wrote:
    > > On Tue, 2018-02-06 at 15:05 +1100, Benjamin Herrenschmidt wrote:
    > > > On Tue, 2018-02-06 at 10:38 +0800, Ryder Lee wrote:
    > > > >
    > > > > I think the code should look at the bridge address <0x0800 ...> we list
    > > > > in bindings for resolving interrupts in this case, but it seems like it
    > > > > use the 'pdev->defvn << 8' which is not really we want and will lead to
    > > > > mismatch.
    > > > >
    > > > > interrupt-map-mask = <0xf800 0 0 7>;
    > > > > interrupt-map = <0x0000 0 0 1 ...>,
    > > > > <0x0000 0 0 2 ...>,
    > > > > <0x0000 0 0 3 ...>,
    > > > > <0x0000 0 0 4 ...>,
    > > > >
    > > > > 0x0800 0 0 1 ...>,
    > > > > 0x0800 0 0 2 ...>,
    > > > > 0x0800 0 0 3 ...>,
    > > > > 0x0800 0 0 4 ...>;
    > > > > ...
    > > > > pcie@1,0 {
    > > > > reg = <0x0800 0 0 0 0>;
    > > > > ...
    > > > > };
    > > > >
    > > > >
    > > > > Or, alternatively, we could add a interrupt-map property in both child
    > > > > and root node to solve this. The below example is my original version as
    > > > > I don't want to change that function either.
    > > >
    > > > The code looks at devfn because it's meant to work for PCI including
    > > > when the devices dont have a device node in the DT.
    > > >
    > > > What I'm trying to figure out is what is it that your parent and
    > > > children are representing here. Which is/are the root complex ?
    > >
    > > This is a single root complex with 2 root port (children in DT).
    > >
    > > > What is the actual topology as visible on the PCIe bus (is lspci output
    > > > basically) and how does that map to your representation ?
    > >
    > > # lspci
    > > 00:00.0 Class 0604: 14c3:0801 //1st slot - pcie@0,0
    > > 00:01.0 Class 0604: 14c3:0801 //2nd slot - pcie@1,0
    > >
    > > 01:00.0 Class 0280: 14c3:7603 //A device which is connected to 1st slot
    > > 02:00.0 Class 0200: 8086:1521 //A 4 func device which is connected to
    > > 2nd slot
    > > 02:00.1 Class 0200: 8086:1521
    > > 02:00.2 Class 0200: 8086:1521
    > > 02:00.3 Class 0200: 8086:1521
    >
    > Ok so that's a rather standard setup. The "devfn << 8" of your root
    > ports should be the exact same thing as their first reg property entry,
    > I'm not sure why you have a mismatch here.

    I've added some log after 'for loop':

    pr_err("busn=0x%x, devfn=0x%x, reg=0x%x\n", pdev->bus->number, pdev->devfn, of_pci_get_devfn(ppnode));

    and got these:

    [ 5.651836] busn=0x0, devfn=0x0, reg=0x0
    [ 5.651936] pcieport 0000:00:00.0: assign IRQ: got 213
    ...
    [ 5.652398] busn=0x0, devfn=0x8, reg=0x0
    [ 5.652487] pcieport 0000:00:01.0: assign IRQ: got 214

    ...
    [ 5.653025] busn=0x2, devfn=0x0, reg=0x8
    [ 5.653058] igb 0000:02:00.0: assign IRQ: got 213

    [ 5.724582] busn=0x2, devfn=0x1, reg=0x8
    [ 5.724634] igb 0000:02:00.1: assign IRQ: got 213

    > However, that map only represents the INTA..D lines going to the root
    > ports, not how these get mapped to children of the root ports.
    >
    > of_irq_parse_pci() will implement standard swizzling if you don't have
    > nodes for your devices at all. If you do, however, the code assumes
    > you have a correct and complete interrupt tree in the device-tree.
    >
    > That means that you need in each "p2p bridge", including your root
    > ports, an interrupt-map that will map the children INTA...D of that
    > bridge to the parent INTA...D of that bridge.
    >
    > Alternatively, you can make the maps in the root ports point directly
    > to the parent PIC. If you chose to do that, then the interrupt-map in
    > your root complex becomes only useful to represent the root ports own
    > interrutps (hotplug, AER,...) and could be replaced by just having
    > interrupt-parent & interrupts in those root port nodes.
    >

    Thanks for explanation.

    So I guess the better way to achieve my aim - one IRQ per slot that is
    connected to all INTx and get propagated through the bridges (and for
    those root ports own interrupts (PME ..)} is to add interrupt-map
    properties in both parent and root port nodes.

    Something like this: https://patchwork.kernel.org/patch/9970923/ ,right?

    Ryder

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