[Skiboot] [PATCH v11 22/23] core/opal: Extend opal_pci_set_power_state()

[Gavin Shan]

On Wed, Jun 08, 2016 at 05:59:44PM +1000, Andrew Donnellan wrote:
>On 08/06/16 17:34, Stewart Smith wrote:
>>I guess the reason that you want to offline then online rather than just
>>rescan is that you may need to update what's on the card while it's
>>offline? Except that the card will be offline... so not sure how that
>>would work?
>>
>>Why not a RESCAN rather than OFFLINE/ONLINE pair?
>
>Right now, I'd be quite happy with a RESCAN rather than OFFLINE/ONLINE - my
>current cxl driver code is switch-to-CAPI-mode -> OFFLINE -> ONLINE. I think
>this option was mentioned in our in-person discussions about how this should
>work. I can't personally think of a usecase where the OFFLINE/ONLINE pair is
>more useful, though Gavin may have other thoughts there.
>

It's all about the granularity we can have. With OFFLINE/ONLINE, more
granularity is given comparing to RESCAN. EEH potentially offline all
devices behind a PCI slot upon excessive errors in future. So I think
OFFLINE/ONLINE seems more reasonable.

Thanks,
Gavin

>
>Andrew
>
>-- 
>Andrew Donnellan              OzLabs, ADL Canberra
>andrew.donnellan at au1.ibm.com  IBM Australia Limited