Hello, On Thu, 16 Jun 2016 11:22:02 +0200, Arnd Bergmann wrote: > > >> + reset-names = "core", "mgmt", "mgmt-sticky", "pipe"; > > >> + phys = <&pcie_phy>; > > >> + phy-names = "pcie-phy"; > > >> + pinctrl-names = "default"; > > >> + pinctrl-0 = <&pcie_clkreq>; > > >> + #interrupt-cells = <1>; > > >> + interrupt-controller; > > >> + interrupt-map-mask = <0 0 0 7>; > > >> + interrupt-map = <0 0 0 1 &pcie0 1>, > > >> + <0 0 0 2 &pcie0 2>, > > >> + <0 0 0 3 &pcie0 3>, > > >> + <0 0 0 4 &pcie0 4>; > > >> +}; > > >> > > > > > > One thing that came up in the review of the new Marvell PCIe driver is that it's > > > most likely invalid for a device node to have both "interrupt-controller" > > > and "interrupt-map" properties. I originally thought this was a nice way to > > > handle embedded irqchips within the PCIe host, but it only really works > > > by coincidence with the current kernel, and only as long as the hwirq number > > > of the irqchip matches the integer representation of the irq line in the root > > > bridge (which it does in the example above). > > > > > > For that driver we concluded that it would be less of a hack to have the > > > irqchip as a child node of the PCIe host after all (just not with > > > device_type="pci" of course), and that makes the translation work as > > > expected. > > > > > > Arnd > > > > > > > Original driver have an irqchip as child node. But Marc suggested don't > > need an intermediate node here. > > Now the conclusion is to retain the child node? > > That is at least my view of the situation, sorry for the mixed messages > you have been getting. Marc, Rob, do you agree with my finding? > > If we want to allow having both interrupt-map and interrupt-controller > in the same node, we need to rewrite both the irq parsing function and > have extend the DT binding for the interrupt-map to explain what we > actually expect to happen in that case. At the moment, we walk up the > tree until we find either an interrupt-map or an interrupt-controller > property, and use that to map the interrupt number. If we find an > interrupt-controller, we ignore the interrupt-map. I can confirm what Arnd said. If you have the following interrupt-map property: + interrupt-map = <0 0 0 1 &pcie0 0>, + <0 0 0 2 &pcie0 1>, + <0 0 0 3 &pcie0 2>, + <0 0 0 4 &pcie0 3>; Then the hwirq you get in the ->map() function are [ 1 ; 4 ] instead of the expected [ 0 ; 3 ]. I.e the translation to the interrupt number in the "target" interrupt controller does not happen. Now, the question is whether this is a bug *or* whether having interrupt-map pointing to its own node is not a valid situation. Thomas -- Thomas Petazzoni, CTO, Free Electrons Embedded Linux, Kernel and Android engineering http://free-electrons.com -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
