Thread (50 messages) 50 messages, 7 authors, 2016-06-12

Re: [PATCH v9 08/14] usb: otg: add OTG/dual-role core

From: Peter Chen <hidden>
Date: 2016-06-08 12:48:01
Also in: linux-omap, lkml

On Wed, Jun 08, 2016 at 01:12:10PM +0300, Roger Quadros wrote:
Hi,

On 08/06/16 12:53, Peter Chen wrote:
quoted
On Wed, Jun 08, 2016 at 12:03:40PM +0300, Roger Quadros wrote:
quoted
+int usb_otg_unregister(struct device *dev)
+{
+	struct usb_otg *otg;
+
+	mutex_lock(&otg_list_mutex);
+	otg = usb_otg_get_data(dev);
+	if (!otg) {
+		dev_err(dev, "otg: %s: device not in otg list\n",
+			__func__);
+		mutex_unlock(&otg_list_mutex);
+		return -EINVAL;
+	}
+
+	/* prevent unregister till both host & gadget have unregistered */
+	if (otg->host || otg->gadget) {
+		dev_err(dev, "otg: %s: host/gadget still registered\n",
+			__func__);
You need to call mutex_unlock here
Indeed. good catch.
quoted
quoted
+
+int usb_otg_gadget_ready(struct usb_gadget *gadget, bool ready)
+{
What this API is for? Why need it in this version?
we moved gadget to otg registration from udc_bind_to_driver() to usb_add_gadget_udc_release().
This means there is a window when gadget function driver (e.g. g_zero) is not loaded.
We don't want to start the gadget controller in that window.

usb_otg_gadget_ready() is used by gadget core to notify the otg core when the function driver
is ready or not-ready.
Why you need to move this from gadget's probe to udc's probe? Currently,
the sequence of gadget and udc's probe is random, but udc_bind_to_driver
is called when udc is ready.

-- 

Best Regards,
Peter Chen
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