Hi Sakari On 20/10/2020 11:05, Sakari Ailus wrote: > Hi Daniel, Andy, > > On Mon, Oct 19, 2020 at 11:58:55PM +0100, Daniel Scally wrote: >> Software nodes that are children of another software node should be >> unregistered before their parent. To allow easy unregistering of an array >> of software_nodes ordered parent to child, add a helper function to loop >> over and unregister nodes in such an array in reverse order. >> >> Suggested-by: Andriy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx> >> Signed-off-by: Daniel Scally <djrscally@xxxxxxxxx> >> --- >> Changes in v3: >> - patch introduced. >> >> drivers/base/swnode.c | 21 +++++++++++++++++++++ >> include/linux/property.h | 1 + >> 2 files changed, 22 insertions(+) >> >> diff --git a/drivers/base/swnode.c b/drivers/base/swnode.c >> index 010828fc7..f01b1cc61 100644 >> --- a/drivers/base/swnode.c >> +++ b/drivers/base/swnode.c >> @@ -727,6 +727,27 @@ void software_node_unregister_nodes(const struct software_node *nodes) >> } >> EXPORT_SYMBOL_GPL(software_node_unregister_nodes); >> >> +/** >> + * software_node_unregister_nodes_reverse - Unregister an array of software >> + * nodes in reverse order. >> + * @nodes: Array of software nodes to be unregistered. >> + * >> + * NOTE: The same warning applies as with software_node_unregister_nodes. >> + * Unless you are _sure_ that the array of nodes is ordered parent to child >> + * it is wiser to remove them individually in the correct order. > Could the default order in software_node_unregister_nodes() be reversed > instead? There are no users so this should be easy to change. > > Doing this only one way may require enforcing the registration order in > software_node_register_nodes(), but the end result would be safer. > > What do you think? Yeah fine by me. We can just use software_node_to_swnode(node->parent) within software_node_unregister_nodes() to check that children come after their parents have already been processed. I'll add a patch to do that in the next version of this series, and another changing the ordering of software_node_unregister_node_group() as Andy suggests for consistency.
