usb: dwc2: gadget: fix fifo allocation leak

When selecting different alt setting, s3c_hsotg_ep_enable can be
called with fifo already allocated. Allocate fifo again only if
required and after deallocating the previous fifo.
Tested-by: NRobert Baldyga <r.baldyga@samsung.com>
Acked-by: NPaul Zimmerman <paulz@synopsys.com>
Signed-off-by: NMian Yousaf Kaukab <yousaf.kaukab@intel.com>
Signed-off-by: NFelipe Balbi <balbi@ti.com>

drivers/usb/dwc2/gadget.c

@@ -2528,11 +2528,22 @@ static int s3c_hsotg_ep_enable(struct usb_ep *ep,
 		break;
 	}
 
+	/* If fifo is already allocated for this ep */
+	if (hs_ep->fifo_index) {
+		size =  hs_ep->ep.maxpacket * hs_ep->mc;
+		/* If bigger fifo is required deallocate current one */
+		if (size > hs_ep->fifo_size) {
+			hsotg->fifo_map &= ~(1 << hs_ep->fifo_index);
+			hs_ep->fifo_index = 0;
+			hs_ep->fifo_size = 0;
+		}
+	}
+
 	/*
 	 * if the hardware has dedicated fifos, we must give each IN EP
 	 * a unique tx-fifo even if it is non-periodic.
 	 */
-	if (dir_in && hsotg->dedicated_fifos) {
+	if (dir_in && hsotg->dedicated_fifos && !hs_ep->fifo_index) {
 		u32 fifo_index = 0;
 		u32 fifo_size = UINT_MAX;
 		size = hs_ep->ep.maxpacket*hs_ep->mc;