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

Murali Karicheri
2014-07-18T20:17:18Z

On 07/18/2014 03:50 PM, Arnd Bergmann 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.
Arnd,

Thanks. I agree with Arnd and believe there is no issue here

> Arnd
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