Re: [PATCH 2/2] powerpc/pseries/dlpar: Remove DT entries if failure from CPU ADD notifier

[Rob Herring <robh@kernel.org>]

On Tue, Sep 15, 2026 at 09:32:49PM -0700, Haren Myneni wrote:
> For CPU ADD, the device tree entries are retrieved with
> configure-connector RTAS call and attached to the device tree.
> Then the CPU is added as part of DT node notification. If the CPU
> ADD notifier returns failure, the corresponding CPU node entries
> should be deleted from the device-tree. See pseries_add_processor()
> for the possible failure cases.
> 
> The current code does not remove CPU node entries during CPU ADD
> notifier failure and causing the following issues:
> - Can not add this CPU later since already present in the
>   device-tree.
> - Trying to free memory allocated to CPU node without detaching
>   the node and it causes freeing its sibling node (existing CPU
>   nodes).
> 
> This patch fixes this issue by calling of_detach_node_no_notify()
> for the failure from CPU ADD notifier which removes CPU node
> entries without calling CPU REMOVE notifier.

Would using the of_changeset_ API directly solve your issue? It's better 
designed for handling reverting a changeset. The of_attach_node/ 
of_detach_node() APIs have limited users and I'd really like to remove 
them. Or make them PPC specific perhaps. Looks like there is 1 non-PPC 
user that snuck in.

Rob