[0/7] PCI irq mapping fixes and cleanups

On Mon, Mar 3, 2014 at 12:11 AM, Jingoo Han <jg1.han@samsung.com> wrote:
> On Sunday, March 02, 2014 3:31 AM, Jason Gunthorpe wrote:
>> On Fri, Feb 28, 2014 at 04:53:33PM -0800, Tim Harvey wrote:
>>
>> > In testing this on IMX6 I'm finding that 'of_irq_parse_and_map_pci()'
>> > always returns -EINVAL because it can't find a dt node for the host
>> > bridge:
>> http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/tree/drivers/of/of_pci_irq.c#n60.
>>
>> There may be some kind of issue in the pcie-designware.c:
>>
>> static struct pci_bus *dw_pcie_scan_bus(int nr, struct pci_sys_data *sys)
>> {
>>         struct pci_bus *bus;
>>         struct pcie_port *pp = sys_to_pcie(sys);
>>
>>         if (pp) {
>>                 pp->root_bus_nr = sys->busnr;
>>                 bus = pci_scan_root_bus(NULL, sys->busnr, &dw_pcie_ops,
>>                                      ^^^^^^^^^^^
>>                                      Shouldn't be null for DT cases.
>>
>> Perhaps since the driver doesn't pass in a parent pointer, no parent
>> device is associated with the struct pci_bus that gets created, so
>> pci_bus_to_OF_node will always fail and the DT PCI mechanisms become
>> broken.
>
> Jason,
> Thank you for your advice. :-)

Jason,

Yes thank you - this does eliminate the -EINVAL from
of_irq_parse_pci() but something still is wrong (see below)

>
> Tim,
> I tested the following as Jason guided.

Jingoo,

Did you test this on in a configuration where devices are behind a
PCIe switch?  I'm still not getting the right IRQ's for that
configuration.

I'm working with the following patch:

The configuration I'm testing is:
root@OpenWrt:/# lspci -n
00:00.0 0604: 16c3:abcd (rev 01)
01:00.0 0604: 10b5:8609 (rev ba)
01:00.1 0880: 10b5:8609 (rev ba)
02:01.0 0604: 10b5:8609 (rev ba)
02:04.0 0604: 10b5:8609 (rev ba)
02:05.0 0604: 10b5:8609 (rev ba)
02:06.0 0604: 10b5:8609 (rev ba)
02:07.0 0604: 10b5:8609 (rev ba)
02:08.0 0604: 10b5:8609 (rev ba)
02:09.0 0604: 10b5:8609 (rev ba)
07:00.0 0280: 168c:002b (rev 01)
08:00.0 0200: 11ab:4380
root@OpenWrt:/# lspci -tnv
-[0000:00]---00.0-[01-09]--+-00.0-[02-09]--+-01.0-[03]--
                           |               +-04.0-[04]--
                           |               +-05.0-[05]--
                           |               +-06.0-[06]--
                           |               +-07.0-[07]----00.0  168c:002b
                           |               +-08.0-[08]----00.0  11ab:4380
                           |               \-09.0-[09]--
                           \-00.1  10b5:8609

The dev_info showing what of_irq_parse_and_map_pci() above produces:
[    1.818485] pci 0000:00:00.0: dw_pcie_map_irq: 16c3:abcd slot0 pin1 irq20
[    1.818703] pci 0000:01:00.0: dw_pcie_map_irq: 10b5:8609 slot0 pin1 irq20
[    1.818939] pci 0000:01:00.1: dw_pcie_map_irq: 10b5:8609 slot0 pin2 irq0
[    1.819179] pci 0000:02:01.0: dw_pcie_map_irq: 10b5:8609 slot0 pin2 irq0
[    1.819395] pci 0000:02:04.0: dw_pcie_map_irq: 10b5:8609 slot0 pin1 irq20
[    1.819631] pci 0000:02:05.0: dw_pcie_map_irq: 10b5:8609 slot0 pin2 irq0
[    1.819859] pci 0000:02:06.0: dw_pcie_map_irq: 10b5:8609 slot0 pin3 irq0
[    1.820087] pci 0000:02:07.0: dw_pcie_map_irq: 10b5:8609 slot0 pin4 irq0
[    1.820404] pci 0000:02:08.0: dw_pcie_map_irq: 10b5:8609 slot0 pin1 irq20
[    1.820650] pci 0000:02:09.0: dw_pcie_map_irq: 10b5:8609 slot0 pin2 irq0
[    1.820881] pci 0000:07:00.0: dw_pcie_map_irq: 168c:002b slot0 pin4 irq0
[    1.821100] pci 0000:08:00.0: dw_pcie_map_irq: 11ab:4380 slot0 pin1 irq20

I'm not clear why irq 20 is getting returned for all the slots with
(slot%4)=0 and func=0.  If I start debugging of_irq_parse_pci() I see
that it walks up the tree until it gets to the pcie host controller
then calls of_irq_parse_raw() which is returning irq20 or -EINVAL.

Tim

> You can test i.MX PCIe with this.
>
> ./drivers/pci/host/pcie-designware.c
> @@ -726,7 +727,7 @@ static struct pci_bus *dw_pcie_scan_bus(int nr, struct pci_sys_data *sys)
>
>         if (pp) {
>                 pp->root_bus_nr = sys->busnr;
> -               bus = pci_scan_root_bus(NULL, sys->busnr, &dw_pcie_ops,
> +               bus = pci_scan_root_bus(pp->dev, sys->busnr, &dw_pcie_ops,
>                                         sys, &sys->resources);
>         } else {
>                 bus = NULL;
>
> However, I think that we may need to replace 'pci_common_init()'
> with 'pci_common_init_dev()'.
>
> Best regards,
> Jingoo Han
>
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[0/7] PCI irq mapping fixes and cleanups

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