usb: dwc3: gadget: Initialize the TRB ring

Clears out all the TRBs in the ring to clean up any stale data that
might be in them from the previous time the endpoint was enabled.

Also removed the existing clear of the LINK trb since the entire ring is
cleard just before.
Signed-off-by: John Youn <johnyoun@synopsys.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>

drivers/usb/dwc3/gadget.c

@@ -585,12 +585,16 @@ static int __dwc3_gadget_ep_enable(struct dwc3_ep *dep,
 		if (usb_endpoint_xfer_control(desc))
 			return 0;
 
+		/* Initialize the TRB ring */
+		dep->trb_dequeue = 0;
+		dep->trb_enqueue = 0;
+		memset(dep->trb_pool, 0,
+		       sizeof(struct dwc3_trb) * DWC3_TRB_NUM);
+
 		/* Link TRB. The HWO bit is never reset */
 		trb_st_hw = &dep->trb_pool[0];
 
 		trb_link = &dep->trb_pool[DWC3_TRB_NUM - 1];
-		memset(trb_link, 0, sizeof(*trb_link));
-
 		trb_link->bpl = lower_32_bits(dwc3_trb_dma_offset(dep, trb_st_hw));
 		trb_link->bph = upper_32_bits(dwc3_trb_dma_offset(dep, trb_st_hw));
 		trb_link->ctrl |= DWC3_TRBCTL_LINK_TRB;