usb-core: Track if an endpoint has streams

This is a preparation patch for adding support for bulk streams to usbfs.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
diff --git a/drivers/usb/core/hcd.c b/drivers/usb/core/hcd.c
index 9b445f4..9c4e292 100644
--- a/drivers/usb/core/hcd.c
+++ b/drivers/usb/core/hcd.c
@@ -2049,7 +2049,7 @@
 {
 	struct usb_hcd *hcd;
 	struct usb_device *dev;
-	int i;
+	int i, ret;
 
 	dev = interface_to_usbdev(interface);
 	hcd = bus_to_hcd(dev->bus);
@@ -2058,13 +2058,24 @@
 	if (dev->speed != USB_SPEED_SUPER)
 		return -EINVAL;
 
-	/* Streams only apply to bulk endpoints. */
-	for (i = 0; i < num_eps; i++)
+	for (i = 0; i < num_eps; i++) {
+		/* Streams only apply to bulk endpoints. */
 		if (!usb_endpoint_xfer_bulk(&eps[i]->desc))
 			return -EINVAL;
+		/* Re-alloc is not allowed */
+		if (eps[i]->streams)
+			return -EINVAL;
+	}
 
-	return hcd->driver->alloc_streams(hcd, dev, eps, num_eps,
+	ret = hcd->driver->alloc_streams(hcd, dev, eps, num_eps,
 			num_streams, mem_flags);
+	if (ret < 0)
+		return ret;
+
+	for (i = 0; i < num_eps; i++)
+		eps[i]->streams = ret;
+
+	return ret;
 }
 EXPORT_SYMBOL_GPL(usb_alloc_streams);
 
@@ -2086,19 +2097,26 @@
 {
 	struct usb_hcd *hcd;
 	struct usb_device *dev;
-	int i;
+	int i, ret;
 
 	dev = interface_to_usbdev(interface);
 	hcd = bus_to_hcd(dev->bus);
 	if (dev->speed != USB_SPEED_SUPER)
 		return -EINVAL;
 
-	/* Streams only apply to bulk endpoints. */
+	/* Double-free is not allowed */
 	for (i = 0; i < num_eps; i++)
-		if (!eps[i] || !usb_endpoint_xfer_bulk(&eps[i]->desc))
+		if (!eps[i] || !eps[i]->streams)
 			return -EINVAL;
 
-	return hcd->driver->free_streams(hcd, dev, eps, num_eps, mem_flags);
+	ret = hcd->driver->free_streams(hcd, dev, eps, num_eps, mem_flags);
+	if (ret < 0)
+		return ret;
+
+	for (i = 0; i < num_eps; i++)
+		eps[i]->streams = 0;
+
+	return ret;
 }
 EXPORT_SYMBOL_GPL(usb_free_streams);