Linux-libre 4.5-gnu

1 files changed, 46 insertions, 34 deletions

diff --git a/drivers/usb/gadget/udc/udc-core.c b/drivers/usb/gadget/udc/udc-core.c
index f660afba7..b86a6f035 100644
--- a/drivers/usb/gadget/udc/udc-core.c
+++ b/drivers/usb/gadget/udc/udc-core.c
@@ -51,8 +51,12 @@ struct usb_udc {
 
 static struct class *udc_class;
 static LIST_HEAD(udc_list);
+static LIST_HEAD(gadget_driver_pending_list);
 static DEFINE_MUTEX(udc_lock);
 
+static int udc_bind_to_driver(struct usb_udc *udc,
+		struct usb_gadget_driver *driver);
+
 /* ------------------------------------------------------------------------- */
 
 #ifdef	CONFIG_HAS_DMA
@@ -356,6 +360,7 @@ int usb_add_gadget_udc_release(struct device *parent, struct usb_gadget *gadget,
 		void (*release)(struct device *dev))
 {
 	struct usb_udc		*udc;
+	struct usb_gadget_driver *driver;
 	int			ret = -ENOMEM;
 
 	udc = kzalloc(sizeof(*udc), GFP_KERNEL);
@@ -403,6 +408,19 @@ int usb_add_gadget_udc_release(struct device *parent, struct usb_gadget *gadget,
 	usb_gadget_set_state(gadget, USB_STATE_NOTATTACHED);
 	udc->vbus = true;
 
+	/* pick up one of pending gadget drivers */
+	list_for_each_entry(driver, &gadget_driver_pending_list, pending) {
+		if (!driver->udc_name || strcmp(driver->udc_name,
+						dev_name(&udc->dev)) == 0) {
+			ret = udc_bind_to_driver(udc, driver);
+			if (ret != -EPROBE_DEFER)
+				list_del(&driver->pending);
+			if (ret)
+				goto err4;
+			break;
+		}
+	}
+
 	mutex_unlock(&udc_lock);
 
 	return 0;
@@ -473,10 +491,14 @@ void usb_del_gadget_udc(struct usb_gadget *gadget)
 
 	mutex_lock(&udc_lock);
 	list_del(&udc->list);
-	mutex_unlock(&udc_lock);
 
-	if (udc->driver)
+	if (udc->driver) {
+		struct usb_gadget_driver *driver = udc->driver;
+
 		usb_gadget_remove_driver(udc);
+		list_add(&driver->pending, &gadget_driver_pending_list);
+	}
+	mutex_unlock(&udc_lock);
 
 	kobject_uevent(&udc->dev.kobj, KOBJ_REMOVE);
 	flush_work(&gadget->work);
@@ -520,50 +542,36 @@ err1:
 	return ret;
 }
 
-int usb_udc_attach_driver(const char *name, struct usb_gadget_driver *driver)
-{
-	struct usb_udc *udc = NULL;
-	int ret = -ENODEV;
-
-	mutex_lock(&udc_lock);
-	list_for_each_entry(udc, &udc_list, list) {
-		ret = strcmp(name, dev_name(&udc->dev));
-		if (!ret)
-			break;
-	}
-	if (ret) {
-		ret = -ENODEV;
-		goto out;
-	}
-	if (udc->driver) {
-		ret = -EBUSY;
-		goto out;
-	}
-	ret = udc_bind_to_driver(udc, driver);
-out:
-	mutex_unlock(&udc_lock);
-	return ret;
-}
-EXPORT_SYMBOL_GPL(usb_udc_attach_driver);
-
 int usb_gadget_probe_driver(struct usb_gadget_driver *driver)
 {
 	struct usb_udc		*udc = NULL;
-	int			ret;
+	int			ret = -ENODEV;
 
 	if (!driver || !driver->bind || !driver->setup)
 		return -EINVAL;
 
 	mutex_lock(&udc_lock);
-	list_for_each_entry(udc, &udc_list, list) {
-		/* For now we take the first one */
-		if (!udc->driver)
+	if (driver->udc_name) {
+		list_for_each_entry(udc, &udc_list, list) {
+			ret = strcmp(driver->udc_name, dev_name(&udc->dev));
+			if (!ret)
+				break;
+		}
+		if (!ret && !udc->driver)
 			goto found;
+	} else {
+		list_for_each_entry(udc, &udc_list, list) {
+			/* For now we take the first one */
+			if (!udc->driver)
+				goto found;
+		}
 	}
 
-	pr_debug("couldn't find an available UDC\n");
+	list_add_tail(&driver->pending, &gadget_driver_pending_list);
+	pr_info("udc-core: couldn't find an available UDC - added [%s] to list of pending drivers\n",
+		driver->function);
 	mutex_unlock(&udc_lock);
-	return -ENODEV;
+	return 0;
 found:
 	ret = udc_bind_to_driver(udc, driver);
 	mutex_unlock(&udc_lock);
@@ -589,6 +597,10 @@ int usb_gadget_unregister_driver(struct usb_gadget_driver *driver)
 			break;
 		}
 
+	if (ret) {
+		list_del(&driver->pending);
+		ret = 0;
+	}
 	mutex_unlock(&udc_lock);
 	return ret;
 }