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>

diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c
index 2b6e7e0..b5e5b35 100644 (file)
--- 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);
        }