[PATCH 3.16 39/63] usb: gadget: rndis: free response queue during REMOTE_NDIS_RESET_MSG

[Ben Hutchings]

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

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

From: Xerox Lin <xerox_lin@xxxxxxx>

commit 207707d8fd48ebc977fb2b2794004a020e1ee08e upstream.

When rndis data transfer is in progress, some Windows7 Host PC is not
sending the GET_ENCAPSULATED_RESPONSE command for receiving the response
for the previous SEND_ENCAPSULATED_COMMAND processed.

The rndis function driver appends each response for the
SEND_ENCAPSULATED_COMMAND in a queue. As the above process got corrupted,
the Host sends a REMOTE_NDIS_RESET_MSG command to do a soft-reset.
As the rndis response queue is not freed, the previous response is sent
as a part of this REMOTE_NDIS_RESET_MSG's reset response and the Host
block any more Rndis transfers.

Hence free the rndis response queue as a part of this soft-reset so that
the correct response for REMOTE_NDIS_RESET_MSG is sent properly during the
response command.

Signed-off-by: Rajkumar Raghupathy <raghup@xxxxxxxxxxxxxx>
Signed-off-by: Xerox Lin <xerox_lin@xxxxxxx>
[AmitP: Cherry-picked this patch and folded other relevant
        fixes from Android common kernel android-4.4]
Signed-off-by: Amit Pundir <amit.pundir@xxxxxxxxxx>
Signed-off-by: Felipe Balbi <felipe.balbi@xxxxxxxxxxxxxxx>
Cc: Arnd Bergmann <arnd@xxxxxxxx>
[bwh: Backported to 3.16:
 - Pass configNr instead of params as first argument to
   rndis_{get_next,free}_response()
 - Adjust filename, context]
Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx>
---
 drivers/usb/gadget/rndis.c | 6 ++++++
 1 file changed, 6 insertions(+)

--- a/drivers/usb/gadget/rndis.c
+++ b/drivers/usb/gadget/rndis.c
@@ -686,6 +686,12 @@ static int rndis_reset_response(int conf
 	rndis_reset_cmplt_type *resp;
 	rndis_resp_t *r;
 	struct rndis_params *params = rndis_per_dev_params + configNr;
+	u8 *xbuf;
+	u32 length;
+
+	/* drain the response queue */
+	while ((xbuf = rndis_get_next_response(configNr, &length)))
+		rndis_free_response(configNr, xbuf);
 
 	r = rndis_add_response(configNr, sizeof(rndis_reset_cmplt_type));
 	if (!r)