[37/83] usb: dwc3: gadget: free trb pool only from epnum 2

From: Ben Hutchings
Date: Sun Jun 16 2013 - 18:28:55 EST


3.2.47-rc1 review patch. If anyone has any objections, please let me know.

------------------

From: George Cherian <george.cherian@xxxxxx>

commit 5bf8fae33d14cc5c3c53a926f9079f92c8b082b0 upstream.

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.

Signed-off-by: George Cherian <george.cherian@xxxxxx>
Signed-off-by: Felipe Balbi <balbi@xxxxxx>
[bwh: Backported to 3.2: adjust context]
Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx>
---
--- a/drivers/usb/dwc3/gadget.c
+++ b/drivers/usb/dwc3/gadget.c
@@ -1310,10 +1310,19 @@ static void dwc3_gadget_free_endpoints(s

for (epnum = 0; epnum < DWC3_ENDPOINTS_NUM; epnum++) {
dep = dwc->eps[epnum];
- 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);
}

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