usb: gadget: aspeed: Cleanup EP0 state on port reset

Otherwise, we can have a stale state after a disconnect and reconnect
causing errors on the first SETUP packet to the device.
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/dev.c

@@ -55,6 +55,9 @@ static void ast_vhub_dev_enable(struct ast_vhub_dev *d)
 	if (d->enabled)
 		return;
 
+	/* Cleanup EP0 state */
+	ast_vhub_reset_ep0(d);
+
 	/* Enable device and its EP0 interrupts */
 	reg = VHUB_DEV_EN_ENABLE_PORT |
 		VHUB_DEV_EN_EP0_IN_ACK_IRQEN |

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

@@ -459,6 +459,15 @@ static const struct usb_ep_ops ast_vhub_ep0_ops = {
 	.free_request	= ast_vhub_free_request,
 };
 
+void ast_vhub_reset_ep0(struct ast_vhub_dev *dev)
+{
+	struct ast_vhub_ep *ep = &dev->ep0;
+
+	ast_vhub_nuke(ep, -EIO);
+	ep->ep0.state = ep0_state_token;
+}
+
+
 void ast_vhub_init_ep0(struct ast_vhub *vhub, struct ast_vhub_ep *ep,
 		       struct ast_vhub_dev *dev)
 {

drivers/usb/gadget/udc/aspeed-vhub/vhub.h

@@ -507,6 +507,7 @@ void ast_vhub_init_hw(struct ast_vhub *vhub);
 /* ep0.c */
 void ast_vhub_ep0_handle_ack(struct ast_vhub_ep *ep, bool in_ack);
 void ast_vhub_ep0_handle_setup(struct ast_vhub_ep *ep);
+void ast_vhub_reset_ep0(struct ast_vhub_dev *dev);
 void ast_vhub_init_ep0(struct ast_vhub *vhub, struct ast_vhub_ep *ep,
 		       struct ast_vhub_dev *dev);
 int ast_vhub_reply(struct ast_vhub_ep *ep, char *ptr, int len);