2013.02.04. 13:13 keltezéssel, Sergei Shtylyov írta:
> Hello.
>
> On 03-02-2013 16:31, Gabor Juhos wrote:
>
>>>> @@ -160,6 +163,16 @@ ath79_register_pci_ar724x(int id,
>>>> res[2].start = irq;
>>>> res[2].end = irq;
>>>>
>>>> + res[3].name = "mem_base";
>>>> + res[3].flags = IORESOURCE_MEM;
>>>> + res[3].start = mem_base;
>>>> + res[3].end = mem_base + mem_size - 1;
>>>> +
>>>> + res[4].name = "io_base";
>>>> + res[4].flags = IORESOURCE_IO;
>>>> + res[4].start = io_base;
>>>> + res[4].end = io_base;
>>>
>>> One I/O port, hm? What is it good for?
>
>> Strictly speaking it is not good for anything. This is a PCIe controller and it
>> does not support IO requests at all.
>
> Is this the case with every PCIe controller or only this particular one?
It is a limitation of this controller.
>
>> However the whole PCI code assumes that
>> each PCI controller have an IO resource and uses the hose->io_resource pointer
>> unconditionally.
>
>> Additionally, this matches with the removed static resource:
>
>>> -static struct resource ar724x_io_resource = {
>>> - .name = "PCI IO space",
>>> - .start = 0,
>>> - .end = 0,
>>> - .flags = IORESOURCE_IO,
>>> -};
>>> -
>
> Since you seems to always pass 0, maybe you don't need 'io_base' parameter to
> the function above?
The AR724x SoCs SoCs have one PCIe controller only. However newer chips have
more than one PCIe controllers, and each of those controllers needs a different
io_base value to avoid resource conflicts. I'm preparing patches for newer SoCs
and if everything goes well I will send those today.
-GAbor
