Patchwork [13/84] usb: dwc3: gadget: free trb pool only from epnum 2

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Submitter Kamal Mostafa
Date June 17, 2013, 5:30 p.m.
Message ID <1371490288-23167-14-git-send-email-kamal@canonical.com>
Download mbox | patch
Permalink /patch/251951/
State New
Headers show

Comments

Kamal Mostafa - June 17, 2013, 5:30 p.m.
3.8.13.3 -stable review patch.  If anyone has any objections, please let me know.

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

From: George Cherian <george.cherian@ti.com>

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@ti.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>
[ kamal: backport to 3.8 ]
Signed-off-by: Kamal Mostafa <kamal@canonical.com>
---
 drivers/usb/dwc3/gadget.c | 14 ++++++++++++--
 1 file changed, 12 insertions(+), 2 deletions(-)

Patch

diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c
index 09835b6..3c0351a 100644
--- a/drivers/usb/dwc3/gadget.c
+++ b/drivers/usb/dwc3/gadget.c
@@ -1627,10 +1627,20 @@  static void dwc3_gadget_free_endpoints(struct dwc3 *dwc)
 
 	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);
 	}