[PATCH 4.15 46/64] usb: dwc3: ep0: Reset TRB counter for ep0 IN

[Greg Kroah-Hartman]

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

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

From: Thinh Nguyen <Thinh.Nguyen@xxxxxxxxxxxx>

commit f035d139ffece7b6a7b8bfb17bd0ba715ee57a04 upstream.

DWC3 tracks TRB counter for each ep0 direction separately. In control
read transfer completion handler, the driver needs to reset the TRB
enqueue counter for ep0 IN direction. Currently the driver only resets
the TRB counter for control OUT endpoint. Check for the data direction
and properly reset the TRB counter from correct control endpoint.

Cc: stable@xxxxxxxxxxxxxxx
Fixes: c2da2ff00606 ("usb: dwc3: ep0: don't use ep0in for transfers")
Signed-off-by: Thinh Nguyen <thinhn@xxxxxxxxxxxx>
Signed-off-by: Felipe Balbi <felipe.balbi@xxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 drivers/usb/dwc3/ep0.c |    7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

--- a/drivers/usb/dwc3/ep0.c
+++ b/drivers/usb/dwc3/ep0.c
@@ -858,7 +858,12 @@ static void dwc3_ep0_complete_data(struc
 		trb++;
 		trb->ctrl &= ~DWC3_TRB_CTRL_HWO;
 		trace_dwc3_complete_trb(ep0, trb);
-		ep0->trb_enqueue = 0;
+
+		if (r->direction)
+			dwc->eps[1]->trb_enqueue = 0;
+		else
+			dwc->eps[0]->trb_enqueue = 0;
+
 		dwc->ep0_bounced = false;
 	}