usb: dwc3: gadget: free trb pool only from epnum 2

we never allocate a TRB pool for physical endpoints
0 and 1 so trying to free it (a invalid TRB pool pointer)
will lead us in a warning while removing dwc3.ko module.

In order to fix the situation, all we have to do is skip
dwc3_free_trb_pool() for physical endpoints 0 and 1 just
as we while deleting endpoints from the endpoints list.

Cc: stable@vger.kernel.org
Signed-off-by: George Cherian <george.cherian@ti.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>

1 files changed, 12 insertions, 4 deletions

diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c
index 2b6e7e001207..b5e5b35df49c 100644
--- a/drivers/usb/dwc3/gadget.c
+++ b/drivers/usb/dwc3/gadget.c
@@ -1706,11 +1706,19 @@ static void dwc3_gadget_free_endpoints(struct dwc3 *dwc)
                 dep = dwc->eps[epnum];
                 if (!dep)
                         continue;
-
-                dwc3_free_trb_pool(dep);
-
-                if (epnum != 0 && epnum != 1)
+                /*
+                 * Physical endpoints 0 and 1 are special; they form the
+                 * bi-directional USB endpoint 0.
+                 *
+                 * For those two physical endpoints, we don't allocate a TRB
+                 * pool nor do we add them the endpoints list. Due to that, we
+                 * shouldn't do these two operations otherwise we would end up
+                 * with all sorts of bugs when removing dwc3.ko.
+                 */
+                if (epnum != 0 && epnum != 1) {
+                        dwc3_free_trb_pool(dep);
                         list_del(&dep->endpoint.ep_list);
+                }
 
                 kfree(dep);
         }