On Fri, Aug 30, 2024 at 11:49:39AM -0400, Frank Li wrote:
> On Thu, Aug 29, 2024 at 05:00:05PM -0500, Bjorn Helgaas wrote:
> > On Thu, Aug 29, 2024 at 05:43:42PM -0400, Frank Li wrote:
> > > On Thu, Aug 29, 2024 at 04:22:35PM -0500, Bjorn Helgaas wrote:
> > > > On Wed, Aug 28, 2024 at 02:40:33PM -0700, Tim Harvey wrote:
> > > > > Greetings,
> > > > >
> > > > > I have a user that is using an IMX8MM SoC (dwc controller) with a
> > > > > miniPCIe card that has a PEX8112 PCI-to-PCIe bridge to a legacy PCI
> > > > > device and the device is not getting a valid interrupt.
> > > >
> > > > Does pci-imx6.c support INTx at all?
> > >
> > > Yes, dwc controller map INTx message to 4 irq lines, which connect to GIC.
> > > we tested it by add nomsi in kernel command line.
> >
> > Thanks, Frank. Can you point me to the dwc code where this happens?
> > Maybe I can remember this for next time or add a comment to help
> > people find it.
>
> I think it needn't special code to handle this. in dts
>
> interrupt-map = <0 0 0 1 &gic GIC_SPI 125 IRQ_TYPE_LEVEL_HIGH>,
> <0 0 0 2 &gic GIC_SPI 124 IRQ_TYPE_LEVEL_HIGH>,
> <0 0 0 3 &gic GIC_SPI 123 IRQ_TYPE_LEVEL_HIGH>,
> <0 0 0 4 &gic GIC_SPI 122 IRQ_TYPE_LEVEL_HIGH>;
>
> It map INT(A,B,C,D) to 4 GIC irq.
OK, thanks! I guess this happens in the of_irq_parse_pci() path, e.g.:
imx6_pcie_probe
dw_pcie_host_init
devm_pci_alloc_host_bridge
devm_of_pci_bridge_init
bridge->map_irq = of_irq_parse_and_map_pci
pci_device_probe # pci_bus_type.probe
pci_assign_irq
bridge->map_irq()
of_irq_parse_and_map_pci
of_irq_parse_pci
of_irq_parse_one
of_irq_parse_raw
of_get_property(ipar, "interrupt-map", &imaplen)
So there really isn't any mention of INTx directly in imx6 or the dwc
core.
I suppose something like:
- Set CONFIG_DYNAMIC_DEBUG=y
- Boot with kernel parameters:
ignore_loglevel dyndbg="file drivers/pci/* +p; file drivers/of/* +p"
should enable some debug output related to this.
Bjorn
