usb: renesas_usbhs: don't re-allocation pipe buffer

Because pipe buffer allocation is very picky and difficult,
current renesas_usbhs driver is not caring pipe re-allocation.

In this situation, driver will create new pipe without caring old pipe
if "usbhsg_ep_enable" is called after "usbhsg_ep_disable" on current driver.
This mean the limited pipe and buffer will be used as waste.
But it is possible to re-use same buffer to same pipe.

By this patch, driver will initialize pipe when it detected new connection or
new gadget, and doesn't try re-allocation for same pipe in above case.
Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/usb/renesas_usbhs/mod_gadget.c

@@ -787,12 +787,18 @@ static int usbhsg_pipe_disable(struct usbhsg_uep *uep)
 		usbhsg_queue_pop(uep, ureq, -ECONNRESET);
 	}
 
-	uep->pipe->mod_private	= NULL;
-	uep->pipe		= NULL;
-
 	return 0;
 }
 
+static void usbhsg_uep_init(struct usbhsg_gpriv *gpriv)
+{
+	int i;
+	struct usbhsg_uep *uep;
+
+	usbhsg_for_each_uep_with_dcp(uep, gpriv, i)
+		uep->pipe = NULL;
+}
+
 /*
  *
  *		usb_ep_ops
@@ -809,6 +815,13 @@ static int usbhsg_ep_enable(struct usb_ep *ep,
 	unsigned long flags;
 	int ret = -EIO;
 
+	/*
+	 * if it already have pipe,
+	 * nothing to do
+	 */
+	if (uep->pipe)
+		return 0;
+
 	/********************  spin lock ********************/
 	spin_lock_irqsave(lock, flags);
 
@@ -1045,6 +1058,7 @@ static int usbhsg_try_start(struct usbhs_priv *priv, u32 status)
 	 * pipe initialize and enable DCP
 	 */
 	usbhs_pipe_init(priv);
+	usbhsg_uep_init(gpriv);
 	usbhsg_dcp_enable(dcp);
 
 	/*