usb: gadget: aspeed-vhub: Fix SETUP packets with OUT data phase

A couple of bugs in the driver are preventing SETUP packets
with an OUT data phase from working properly.

Interestingly those are incredibly rare (RNDIS typically
uses them and thus is broken without this fix).

The main problem was an incorrect register offset being
applied for arming RX on EP0. The other problem relates
to stalling such a packet before the data phase, in which
case we don't get an ACK cycle, and get the next SETUP
packet directly, so we shouldn't reject it.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>

drivers/usb/gadget/udc/aspeed-vhub/ep0.c

@@ -108,6 +108,13 @@ void ast_vhub_ep0_handle_setup(struct ast_vhub_ep *ep)
 	/* Check our state, cancel pending requests if needed */
 	if (ep->ep0.state != ep0_state_token) {
 		EPDBG(ep, "wrong state\n");
+		ast_vhub_nuke(ep, -EIO);
+
+		/*
+		 * Accept the packet regardless, this seems to happen
+		 * when stalling a SETUP packet that has an OUT data
+		 * phase.
+		 */
 		ast_vhub_nuke(ep, 0);
 		goto stall;
 	}
@@ -224,7 +231,7 @@ static void ast_vhub_ep0_rx_prime(struct ast_vhub_ep *ep)
 	EPVDBG(ep, "rx prime\n");
 
 	/* Prime endpoint for receiving data */
-	writel(VHUB_EP0_RX_BUFF_RDY, ep->ep0.ctlstat + AST_VHUB_EP0_CTRL);
+	writel(VHUB_EP0_RX_BUFF_RDY, ep->ep0.ctlstat);
 }
 
 static void ast_vhub_ep0_do_receive(struct ast_vhub_ep *ep, struct ast_vhub_req *req,