Re: [PATCH v6 4/5] PCI: add PCI controller for keystone PCIe h/w

Rob Herring
2014-07-22T15:37:57Z

On Fri, Jul 18, 2014 at 2:50 PM, Arnd Bergmann <arnd@arndb.de> wrote:
> On Friday 18 July 2014 14:31:39 Rob Herring wrote:
>> > +
>> > + Example:
>> > + pcie_msi_intc: msi-interrupt-controller {
>> > + interrupt-controller;
>> > + #interrupt-cells = <1>;
>> > + interrupt-parent = <&gic>;
>> > + interrupts = <GIC_SPI 30 IRQ_TYPE_EDGE_RISING>,
>> > + <GIC_SPI 31 IRQ_TYPE_EDGE_RISING>,
>> > + <GIC_SPI 32 IRQ_TYPE_EDGE_RISING>,
>> > + <GIC_SPI 33 IRQ_TYPE_EDGE_RISING>,
>> > + <GIC_SPI 34 IRQ_TYPE_EDGE_RISING>,
>> > + <GIC_SPI 35 IRQ_TYPE_EDGE_RISING>,
>> > + <GIC_SPI 36 IRQ_TYPE_EDGE_RISING>,
>> > + <GIC_SPI 37 IRQ_TYPE_EDGE_RISING>;
>> > + };
>> > +
>> > +pcie_intc: Interrupt controller device node for Legacy irq chip
>> > + interrupt-cells: should be set to 1
>> > + interrupt-parent: Parent interrupt controller phandle
>> > + interrupts: GIC interrupt lines connected to PCI Legacy interrupt lines
>> > +
>> > + Example:
>> > + pcie_intc: legacy-interrupt-controller {
>> > + interrupt-controller;
>> > + #interrupt-cells = <1>;
>> > + interrupt-parent = <&gic>;
>> > + interrupts = <GIC_SPI 26 IRQ_TYPE_EDGE_RISING>,
>> > + <GIC_SPI 27 IRQ_TYPE_EDGE_RISING>,
>> > + <GIC_SPI 28 IRQ_TYPE_EDGE_RISING>,
>> > + <GIC_SPI 29 IRQ_TYPE_EDGE_RISING>;
>> > + };
>>
>> This seems wrong. Legacy interrupts should be described with
>> interrupt-map and then PCI child devices have a standard interrupt
>> specifier.
>>
>> I'm not sure about MSIs, but I would think they would have a standard
>> format too.
>>
>
> IIRC, it's actually the correct way to do this here: the problem is that
> the PCI IRQs are not directly connected to the GIC, but instead there is
> a nested irqchip that has each PCI IRQ routed to it and that requires
> an extra EOI for each interrupt.
>
> The interrupt-map in the PCI host points to this special irqchip rather
> than to the GIC.

Okay, if there is still an interrupt-map property, then I agree. This
wasn't clear in the example.

Rob