On Mon, Aug 22, 2016 at 12:09:54PM -0400, Alan Stern wrote:

quoted

quoted

+
+static int hub_of_pwrseq_on(struct device_node *np, struct usb_hub *hub)
+{
+	struct pwrseq *pwrseq;
+	struct usb_pwrseq_node *pwrseq_node;
+	int ret;
+
+	pwrseq = pwrseq_alloc_generic();
+	if (IS_ERR(pwrseq))
+		return PTR_ERR(pwrseq);
+
+	ret = pwrseq_get(np, pwrseq);
+	if (ret)
+		goto pwr_free;
+
+	ret = pwrseq_on(np, pwrseq);
+	if (ret)
+		goto pwr_put;
+
+	pwrseq_node = kzalloc(sizeof(*pwrseq_node), GFP_KERNEL);

You need to check that the kzalloc succeeded.

Ok.

quoted

quoted

+	pwrseq_node->pwrseq = pwrseq;
+	list_add(&pwrseq_node->list, &hub->pwrseq_on_list);
+
+	return 0;
+
+pwr_put:
+	pwrseq_put(pwrseq);
+pwr_free:
+	pwrseq_free(pwrseq);
+	return ret;
+}

This subroutine looks very generic.  The only place where it cares that
it was called for a USB hub is the list_add(), and that could easily
become generic also (make this function take &hub->pwrseq_on_list as
its second argument, instead of hub).

It looks like this routine really belongs in the power sequence 
library.

I will export below two generic functions at pwrseq library:

int generic_pwrseq_on(struct device_node *np, struct list_head *head)
void generic_pwrseq_off(struct list_head *head)

delete this file, and call above APIs at hub.c.

quoted

quoted

+
+int hub_pwrseq_on(struct usb_hub *hub)
+{

The names of this routine and the subroutine above are too similar.  
After all, both functions require OF support.

I will add #ifdef CONFIG_OF for related code. And put the content at
hub_pwrseq_on at hub_probe directly, how about below?

hub_probe() {

	...

	if (hub_configure(hub, endpoint) >= 0) {
#ifdef CONFIG_OF
		for_each_child_of_node(parent->of_node, np) {
			ret = generic_pwrseq_on(np, hub);
			if (ret)
				return ret;
		}
#else
		return 0;
#endif
	}

	hub_disconnect(intf);
	return ret;
}

-- 

Best Regards,
Peter Chen