3.8-stable review patch.  If anyone has any objections, please let me know.

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

From: Pratyush Anand <pratyush.an...@st.com>

commit cdc359dd87ab6c39a67dab724fd0b61c16e6f08b upstream.

There were still some corner cases where isoc transfer was not able to
restart, specially when missed isoc does not happen , and in fact gadget does
not queue any new request during giveback.

Cleanup function calls giveback first, which provides a way to queue
another request to gadget. But gadget did not had any data. So , it did
not call ep_queue. To twist it further, gadget did not queue till
cleanup for last queued TRB is called. If we ever reach this scenario,
we must call END TRANSFER, so that we receive a new  xfernotready with
information about current microframe number.

Also insure that there is no request submitted to core when issuing END
TRANSFER.

Signed-off-by: Pratyush Anand <pratyush.an...@st.com>
Signed-off-by: Felipe Balbi <ba...@ti.com>
Signed-off-by: Greg Kroah-Hartman <gre...@linuxfoundation.org>

---
 drivers/usb/dwc3/gadget.c |   23 ++++++++++++++++++-----
 1 file changed, 18 insertions(+), 5 deletions(-)

--- a/drivers/usb/dwc3/gadget.c
+++ b/drivers/usb/dwc3/gadget.c
@@ -1091,7 +1091,10 @@ static int __dwc3_gadget_ep_queue(struct
                 * notion of current microframe.
                 */
                if (usb_endpoint_xfer_isoc(dep->endpoint.desc)) {
-                       dwc3_stop_active_transfer(dwc, dep->number);
+                       if (list_empty(&dep->req_queued)) {
+                               dwc3_stop_active_transfer(dwc, dep->number);
+                               dep->flags = DWC3_EP_ENABLED;
+                       }
                        return 0;
                }
 
@@ -1728,10 +1731,20 @@ static int dwc3_cleanup_done_reqs(struct
                        break;
        } while (1);
 
-       if (list_empty(&dep->req_queued) &&
-                       (dep->flags & DWC3_EP_MISSED_ISOC)) {
-               dwc3_stop_active_transfer(dwc, dep->number);
-               dep->flags &= ~DWC3_EP_MISSED_ISOC;
+       if (usb_endpoint_xfer_isoc(dep->endpoint.desc) &&
+                       list_empty(&dep->req_queued)) {
+               if (list_empty(&dep->request_list)) {
+                       /*
+                        * If there is no entry in request list then do
+                        * not issue END TRANSFER now. Just set PENDING
+                        * flag, so that END TRANSFER is issued when an
+                        * entry is added into request list.
+                        */
+                       dep->flags = DWC3_EP_PENDING_REQUEST;
+               } else {
+                       dwc3_stop_active_transfer(dwc, dep->number);
+                       dep->flags = DWC3_EP_ENABLED;
+               }
                return 1;
        }
 


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