[Skiboot] [PATCH v2 4/4] npu3: Register virtual PHBs with static IDs

Andrew Donnellan ajd at linux.ibm.com
Thu Sep 26 22:30:09 AEST 2019

On 26/9/19 2:22 pm, Oliver O'Halloran wrote:
> On Thu, Sep 26, 2019 at 10:18 PM Andrew Donnellan <ajd at linux.ibm.com> wrote:
>> On 9/8/19 3:05 pm, Frederic Barrat wrote:
>>> Assigning opal IDs to virtual PHBs dynamically may lead to userland
>>> seeing the PCI domain ID for an adapter vary when adding or removing
>>> another adapter (GPU or opencapi).
>>> This patch switches to using static opal IDs for virtual PHBs, based
>>> on their ibm,phb-index property, which was made static by a previous
>>> patch.
>>> Note that the PCI domain IDs will increase on the second chip (or
>>> more, if we had more) because we now reserve 16 IDs per chip for PHBs.
>> This affects phb4 PHBs on Axone as well? I didn't figure that out
>> immediately when I read the commit message.
> It does, but that's fine. We need to keep the domain numbers the same
> on existing systems since re-numbering them breaks "persistent"
> network device naming.

Yeah I didn't think it was a problem as such, just that a cursory glance 
at this patch without thinking very hard about it might make you think 
the IDs for phb4 PHBs won't change.

In any case:

Reviewed-by: Andrew Donnellan <ajd at linux.ibm.com>

Andrew Donnellan              OzLabs, ADL Canberra
ajd at linux.ibm.com             IBM Australia Limited

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