Re: [PATCH 2/2] pci: host: Add Broadcom STB PCIE RC controller

[Florian Fainelli]

On 05/05/16 10:48, Jim Quinlan wrote:
>>> Why is this?
>>
>> This is so we do not end-up programming the PCIe RC which is agnostic of
>> the number of
> 
> I believe this code is still around for folks passing us a device tree
> with lacking information.  It should be removed.

I have actually reworked this to utilize the brcm,log2-scb-sizes
property, since the number of elements in the property is equal to the
number of memory controllers populated on the system.

> 
>>
>>>
>>>> +    resource_list_for_each_entry(win, &res) {
>>>> +            struct brcm_window *w = &pcie->out_wins[i];
>>>> +
>>>> +            r = win->res;
>>>> +
>>>> +            if (!r->flags)
>>>> +                    continue;
>>>> +
>>>> +            switch (resource_type(r)) {
>>>> +            case IORESOURCE_MEM:
>>>> +                    w->cpu_addr = r->start;
>>>> +                    w->size = resource_size(r);
>>>> +                    w->pcie_iomem_res.name  = "External PCIe MEM";
>>>> +                    w->pcie_iomem_res.flags = r->flags;
>>>> +                    w->pcie_iomem_res.start = r->start;
>>>> +                    w->pcie_iomem_res.end   = r->end;
>>>> +                    pcie->num_out_wins++;
>>>> +                    i++;
>>>> +                    /* Request memory region resources. */
>>>> +                    ret = devm_request_resource(&pdev->dev,
>>>> +                                                &iomem_resource,
>>>> +                                                &w->pcie_iomem_res);
>>>> +                    if (ret) {
>>>> +                            dev_err(&pdev->dev,
>>>> +                                    "request PCIe memory resource failed\n");
>>>> +                            goto out_err_clk;
>>>> +                    }
>>>> +                    break;
>>>> +
>>>> +            default:
>>>> +                    continue;
>>>> +            }
>>>> +    }
>>>
>>> What about IORESOURCE_IO?
>>
>> We do not support I/O space on this controller AFAIR. Our downstream
>> driver does insert a fake bogus I/O range, but I cannot really remember
>> why that was needed now, Jim do you remember?
>> --
>> Florian
> 
> We added a bogus IO region because there was no other way to proceed
> w/o getting an error.  Or should I say, I knew of no other way to
> proceed...

AH, I found your commit doing that, I would really think that the PCI
domains logic should be able to take care of assigning non-conflicting
I/O regions these days, if not, that seems like a bug to me.

Do I need a specific board with a ton of switches/peripherals attached
to it to expose whether this is needed or not? Right now, I removed it
from this patchset, but I suppose we could add it back, would we need that?

Thanks Jim!
-- 
Florian