usb: gadget: clean the ep in autoconf before returning it.

Since commit 72c973dd aka ("usb: gadget: add usb_endpoint_descriptor to
struct usb_ep) the descriptor is part of the ep. Most gadgets like
g_zero or masstorage call config_ep_by_speed() to grab an available
endpoint which may be used for FS/HS/SS bulk/iso/intr and in a second
they assign the proper descriptor by calling config_ep_by_speed(). This
is good so far. A few of them like ncm call config_ep_by_speed() only if
ep->desc not assigned earlier. That means ep->desc is never assigned if
the endpoint was used by another gadget before it was removed.

Some of those gadgets also assign ep->driver_data to NULL on reset or
ep_disable part _but_ keep a reference to this endpoint. At ep_enable
time they assign driver_data to their private data. This probably needs
a clean up of its own.

Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Felipe Balbi <balbi@ti.com>

1 files changed, 10 insertions, 6 deletions

diff --git a/drivers/usb/gadget/epautoconf.c b/drivers/usb/gadget/epautoconf.c
index 753aa0683ac1..f59f7e367b5a 100644
--- a/drivers/usb/gadget/epautoconf.c
+++ b/drivers/usb/gadget/epautoconf.c
@@ -275,24 +275,24 @@ struct usb_ep *usb_ep_autoconfig_ss(
                 /* ep-e, ep-f are PIO with only 64 byte fifos */
                 ep = find_ep (gadget, "ep-e");
                 if (ep && ep_matches(gadget, ep, desc, ep_comp))
-                        return ep;
+                        goto found_ep;
                 ep = find_ep (gadget, "ep-f");
                 if (ep && ep_matches(gadget, ep, desc, ep_comp))
-                        return ep;
+                        goto found_ep;
 
         } else if (gadget_is_goku (gadget)) {
                 if (USB_ENDPOINT_XFER_INT == type) {
                         /* single buffering is enough */
                         ep = find_ep(gadget, "ep3-bulk");
                         if (ep && ep_matches(gadget, ep, desc, ep_comp))
-                                return ep;
+                                goto found_ep;
                 } else if (USB_ENDPOINT_XFER_BULK == type
                                 && (USB_DIR_IN & desc->bEndpointAddress)) {
                         /* DMA may be available */
                         ep = find_ep(gadget, "ep2-bulk");
                         if (ep && ep_matches(gadget, ep, desc,
                                               ep_comp))
-                                return ep;
+                                goto found_ep;
                 }
 
 #ifdef CONFIG_BLACKFIN
@@ -311,18 +311,22 @@ struct usb_ep *usb_ep_autoconfig_ss(
                 } else
                         ep = NULL;
                 if (ep && ep_matches(gadget, ep, desc, ep_comp))
-                        return ep;
+                        goto found_ep;
 #endif
         }
 
         /* Second, look at endpoints until an unclaimed one looks usable */
         list_for_each_entry (ep, &gadget->ep_list, ep_list) {
                 if (ep_matches(gadget, ep, desc, ep_comp))
-                        return ep;
+                        goto found_ep;
         }
 
         /* Fail */
         return NULL;
+found_ep:
+        ep->desc = NULL;
+        ep->comp_desc = NULL;
+        return ep;
 }
 
 /**