usb: musb: dsps: polling ID pin status only in otg mode

Only start the otg_timer in dual role mode; otherwise in peripheral mode
when musb is disconnected from the host port, otg_timer starts and
continuously toggles the session, which causes VBUS pulse.

Signed-off-by: Bin Liu <b-liu@ti.com>
Acked-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Felipe Balbi <balbi@ti.com>
diff --git a/drivers/usb/musb/musb_dsps.c b/drivers/usb/musb/musb_dsps.c
index 7cfa6e8..593d3c9 100644
--- a/drivers/usb/musb/musb_dsps.c
+++ b/drivers/usb/musb/musb_dsps.c
@@ -359,8 +359,9 @@
 	if (musb->int_tx || musb->int_rx || musb->int_usb)
 		ret |= musb_interrupt(musb);
 
-	/* Poll for ID change */
-	if (musb->xceiv->state == OTG_STATE_B_IDLE)
+	/* Poll for ID change in OTG port mode */
+	if (musb->xceiv->state == OTG_STATE_B_IDLE &&
+			musb->port_mode == MUSB_PORT_MODE_DUAL_ROLE)
 		mod_timer(&glue->timer, jiffies + wrp->poll_seconds * HZ);
 out:
 	spin_unlock_irqrestore(&musb->lock, flags);