Hi,

On 08/06/16 12:53, Peter Chen wrote:

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

+
+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.

quoted

+	struct usb_otg *otg;
+	struct device *gadget_dev = &gadget->dev;
+	struct device *otg_dev = gadget->otg_dev;
+
+	if (!otg_dev)
+		return -EINVAL;
+
+	mutex_lock(&otg_list_mutex);
+	otg = usb_otg_get_data(otg_dev);
+	mutex_unlock(&otg_list_mutex);
+	if (!otg) {
+		dev_err(gadget_dev,
+			"otg: gadget %s wasn't registered with otg\n",
+			dev_name(&gadget->dev));
+		return -EINVAL;
+	}
+
+	mutex_lock(&otg->fsm.lock);
+	if (otg->gadget != gadget) {
+		mutex_unlock(&otg->fsm.lock);
+		dev_err(otg_dev, "otg: gadget %s wasn't registered with otg\n",
+			dev_name(&gadget->dev));
+		return -EINVAL;
+	}
+
+	/* Start/stop FSM & gadget */
+	otg->gadget_ready = ready;
+	if (ready)
+		usb_otg_start_fsm(otg);
+	else
+		usb_otg_stop_fsm(otg);
+
+	dev_dbg(otg_dev, "otg: gadget %s %sready\n", dev_name(&gadget->dev),
+		ready ? "" : "not ");
+
+	mutex_unlock(&otg->fsm.lock);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(usb_otg_gadget_ready);
+

--- a/include/linux/usb/otg.h
+++ b/include/linux/usb/otg.h

@@ -10,10 +10,70 @@
 #define __LINUX_USB_OTG_H
 
 #include <linux/phy/phy.h>
-#include <linux/usb/phy.h>
-#include <linux/usb/otg-fsm.h>
+#include <linux/device.h>
+#include <linux/hrtimer.h>
+#include <linux/ktime.h>

The above two timer header files are not needed.

You had pointed this out earlier, but I missed it. Sorry.