RE: [PATCH V2 3/5] PCI: xilinx: Modifying AXI PCIe Host Bridge driver to work on both Zynq and Microblaze

Subject: Re: [PATCH V2 3/5] PCI: xilinx: Modifying AXI PCIe Host Bridge driver
to work on both Zynq and Microblaze

On Thursday 28 January 2016 13:20:56 Bharat Kumar Gogada wrote:

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Subject: Re: [PATCH V2 3/5] PCI: xilinx: Modifying AXI PCIe Host
Bridge driver to work on both Zynq and Microblaze

On Wednesday 27 January 2016 14:33:45 Bharat Kumar Gogada wrote:

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@@ -705,7 +715,9 @@ static int xilinx_pcie_probe(struct

platform_device *pdev)  #endif
    pci_scan_child_bus(bus);
    pci_assign_unassigned_bus_resources(bus);
+#ifdef CONFIG_ARM
    pci_fixup_irqs(pci_common_swizzle,
of_irq_parse_and_map_pci);
+#endif
    pci_bus_add_devices(bus);
    platform_set_drvdata(pdev, port);

Here it looks like microblaze gets it right. I'm not sure why we
still need the
pci_fixup_irqs() on ARM, but my feeling is that this should be
fixed in common code.

In arm pci_fixup_irqs is called by pci_common_init_dev

(arch/arm/kernel/bios32.c), since this API is removed now, I was
calling it separately.

But who calls it in microblaze? If it works without the extra call
there, can we make it work the same way for ARM?

In microblaze I have added pcibios_add_device call (similar to call in
arch/arm64/kernel/pci.c ) in pci-common.c, which is being invoked by
kernel core itself.

I see. In the upstream code you seem to do it in
pcibios_setup_bus_devices(), while arm64 and powerpc do it in
pcibios_add_device().

No that function is not getting called with generic API's, its getting called with pcibios_init flow which is tightly bound with struct pci_controller microblaze specific structure. So I added pcibios_add_device in pci-common.c.

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May be we can add similar on arm and test out, but we might need some
cleanup in arch/arm/kernel/bios32.c

I think that would still just be a half-baked solution. This should really be fully
automatic. We could do it in the __weak
pcibios_add_device() for all architectures that don't override it when the bus
was probed from DT, or we could do it in pci_read_irq().

When will pci_read_irq() call get invoked ?

Bharat