[Skiboot] [PATCH V4 1/3] core/device: Add function to return child node using name at substring "@"

Reza Arbab arbab at linux.ibm.com
Thu Mar 23 07:12:59 AEDT 2023

Hi Athira,

On Mon, Mar 06, 2023 at 09:09:11AM +0530, Athira Rajeev wrote:
>Add a function dt_find_by_name_substr() that returns the child node if
>it matches till first occurence at "@" of a given name, otherwise NULL.

Given this summary, I don't understand the following:

>+	assert(dt_find_by_name_substr(root, "node at 1") == addr1);
>+	assert(dt_find_by_name_substr(root, "node0_1 at 2") == addr2);

Is this behavior required? I don't think it makes sense to call this 
function with a second argument containing '@', so I wouldn't expect it 
to match anything in these cases. The function seems to specifically 
enable it:

>+struct dt_node *dt_find_by_name_substr(struct dt_node *root, const char *name)
>+      node = strdup(name);
>+      if (!node)
>+              return NULL;
>+      node = strtok(node, "@");

Seems like you could get rid of this and just use name as-is.

I was curious about something else; say we have 'node at 1' and 'node at 2'.  
Is there an expectation of which it should match?

     addr1 = dt_new_addr(root, "node", 0x1);
     addr2 = dt_new_addr(root, "node", 0x2);
     assert(dt_find_by_name_substr(root, "node") == ???????);

>+/* Find a child node by name and substring */
>+struct dt_node *dt_find_by_name_substr(struct dt_node *root, const char *name);

I think this name fit better in previous versions of the patch, but 
since you're specifically looking for '@' now, maybe call it something 
like dt_find_by_name_before_addr?

Reza Arbab

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