[Skiboot] [PATCH v4 08/10] core/opal: Switch to PCI slot

[Gavin Shan]

On Wed, Feb 18, 2015 at 01:00:58PM +1100, Stewart Smith wrote:
>Gavin Shan <gwshan at linux.vnet.ibm.com> writes:
>> -opal_call(OPAL_PCI_POLL, opal_pci_poll, 1);
>> +opal_call(OPAL_PCI_POLL, opal_pci_poll, 2);
>
>This looks like a backwards incompatible change? I don't *think* we
>could reasonably add another parameter and have old kernels still work
>correctly?
>

Yes, the change looks subtle to ensure backwords compatibility. With
old firmware + new kernel, PCI slots won't be populated from kernel
side and we don't expect opal_pci_poll() to return additional PCI slot
power or presence status. For new firmware + old kernel, we shouldn't
call opal_pci_poll() when the slot in NORMAL state. Thus the firmware
won't return additional power or presence status and old kernel needn't
them as well.

>It'd also be great if you could add documentation about the new (and
>old) calls as well (in doc/opal-api/ )

I'll add doc/opal-api/opal-pci.txt seperately if you agree. It would
describe all PCI related OPAL calls.

Thanks,
Gavin