Messages in this thread Patch in this message | | | From | Ryder Lee <> | Subject | [PATCH 1/2] of_pci_irq: add a check to fallback to standard device tree parsing | Date | Wed, 31 Jan 2018 15:41:49 +0800 |
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A root complex usually consist of a host bridge and multiple P2P bridges, and someone may express that in the form of a root node with many subnodes and list all four interrupts for each slot (child node) in the root node like this:
pcie-controller { ... interrupt-map-mask = <0xf800 0 0 7>; interrupt-map = <0x0000 0 0 {INTx} &{interrupt parent} ...> 0x0800 0 0 {INTx} &{interrupt parent} ...>;
pcie@0,0 { reg = <0x0000 0 0 0 0>; ... };
pcie@1,0 { reg = <0x0800 0 0 0 0>; ... }; };
As shown above, we'd like to propagate IRQs from a root port to the devices in the hierarchy below it in this way. However, it seems that the current parser couldn't handle such cases and will get something unexpected below:
pcieport 0000:00:01.0: assign IRQ: got 213 igb 0000:01:00.0: assign IRQ: got 212
There is a device which is connected to 2nd slot, but the port doesn't share the same IRQ with its downstream devices. The problem here is that, if the loop found a P2P bridge, it wouldn't check whether the reg property exists in ppnode or not but just pass the subordinate devfn to of_irq_parse_raw(), thus the subsequent flow couldn't correctly resolve them.
Fix this by adding a check to fallback to standard device tree parsing.
Signed-off-by: Ryder Lee <ryder.lee@mediatek.com> --- Please refer to the previous discussion thread: https://patchwork.ozlabs.org/patch/829108/ --- drivers/of/of_pci_irq.c | 14 ++++++++++++-- 1 file changed, 12 insertions(+), 2 deletions(-)
diff --git a/drivers/of/of_pci_irq.c b/drivers/of/of_pci_irq.c index 3a05568..e445866 100644 --- a/drivers/of/of_pci_irq.c +++ b/drivers/of/of_pci_irq.c @@ -86,8 +86,18 @@ int of_irq_parse_pci(const struct pci_dev *pdev, struct of_phandle_args *out_irq out_irq->np = ppnode; out_irq->args_count = 1; out_irq->args[0] = pin; - laddr[0] = cpu_to_be32((pdev->bus->number << 16) | (pdev->devfn << 8)); - laddr[1] = laddr[2] = cpu_to_be32(0); + + if (!dn && ppnode) { + const __be32 *addr; + + addr = of_get_property(ppnode, "reg", NULL); + if (addr) + memcpy(laddr, addr, 3); + } else { + laddr[0] = cpu_to_be32((pdev->bus->number << 16) | (pdev->devfn << 8)); + laddr[1] = laddr[2] = cpu_to_be32(0); + } + rc = of_irq_parse_raw(laddr, out_irq); if (rc) goto err; -- 1.9.1
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