usb: gadget: mv_udc: disable ISR when stopped

When device is stopped, there is no need to handle ISR.
Especially when otg switch to HOST mode.

Signed-off-by: Neil Zhang <zhangwm@marvell.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>

drivers/usb/gadget/mv_udc.h

@@ -211,7 +211,8 @@ struct mv_udc {
 				softconnected:1,
 				force_fs:1,
 				clock_gating:1,
-				active:1;
+				active:1,
+				stopped:1;      /* stop bit is setted */
 
 	struct work_struct	vbus_work;
 	struct workqueue_struct *qwork;

drivers/usb/gadget/mv_udc_core.c

@@ -1056,6 +1056,8 @@ static void udc_stop(struct mv_udc *udc)
 		USBINTR_PORT_CHANGE_DETECT_EN | USBINTR_RESET_EN);
 	writel(tmp, &udc->op_regs->usbintr);
 
+	udc->stopped = 1;
+
 	/* Reset the Run the bit in the command register to stop VUSB */
 	tmp = readl(&udc->op_regs->usbcmd);
 	tmp &= ~USBCMD_RUN_STOP;
@@ -1072,6 +1074,8 @@ static void udc_start(struct mv_udc *udc)
 	/* Enable interrupts */
 	writel(usbintr, &udc->op_regs->usbintr);
 
+	udc->stopped = 0;
+
 	/* Set the Run bit in the command register */
 	writel(USBCMD_RUN_STOP, &udc->op_regs->usbcmd);
 }
@@ -2040,6 +2044,10 @@ static irqreturn_t mv_udc_irq(int irq, void *dev)
 	struct mv_udc *udc = (struct mv_udc *)dev;
 	u32 status, intr;
 
+	/* Disable ISR when stopped bit is set */
+	if (udc->stopped)
+		return IRQ_NONE;
+
 	spin_lock(&udc->lock);
 
 	status = readl(&udc->op_regs->usbsts);