Re: [PATCH V3 7/8] pcie: SPEAr13xx: Add designware pcie support

[Arnd Bergmann <arnd@arndb.de>]

On Thursday 30 January 2014, Arnd Bergmann wrote:
> > +             pcie0: pcie@b1000000 {
> > +                     compatible = "st,spear1340-pcie", "snps,dw-pcie";
> > +                     reg = <0xb1000000 0x4000>;
> > +                     interrupts = <0 68 0x4>;
> > +                     pcie_is_gen1 = <0>;
> > +                     num-lanes = <1>;
> > +                     phys = <&miphy0 1 0>;
> > +                     phy-names = "pcie-phy";
> > +                     #address-cells = <3>;
> > +                     #size-cells = <2>;
> > +                     device_type = "pci";
> > +                     ranges = <0x00000800 0 0x80000000 0x80000000 0 0x00020000   /* configuration space */
> > +                             0x81000000 0 0   0x80020000 0 0x00010000   /* downstream I/O */
> > +                             0x82000000 0 0x80030000 0xc0030000 0 0x0ffd0000>; /* non-prefetchable memory */
> > +                     status = "disabled";
> > +             };
> 
> Shouldn't there be more than one interrupt? Normally each root port has
> four legacy IRQs, in order to support bridge devices.
> 

Sorry, my mistake: I was thinking of the interrupt map for legacy IRQs.
The interrupt here is used only for the integrated MSI controller, right?
That seems fine from the DT bindings perspective but raises two other
questions:

1. Are you not lacking an interrupt-map property to enable legacy IntA
   IRQs?

2. If the MSI controller is integrated in the pcie host controller,
   does that maintain the PCIe ordering guarantees between inbound
   DMA and MSI, or is it possible that the <0 68 0x4> IRQ gets
   raised at the CPU before the the DMA transfer becomes visible to
   the CPU in main memory?

	Arnd