usb: chipidea: udc: don't touch DP when controller is in host mode

BugLink: http://bugs.launchpad.net/bugs/1621113

commit c4e94174 upstream.

When the controller is configured to be dual role and it's in host mode,
if bind udc and gadgt driver, those gadget operations will do gadget
disconnect and finally pull down DP line, which will break host function.
Signed-off-by: Li Jun <jun.li@nxp.com>
Signed-off-by: Peter Chen <peter.chen@nxp.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Tim Gardner <tim.gardner@canonical.com>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>

drivers/usb/chipidea/udc.c

@@ -1585,8 +1585,11 @@ static int ci_udc_pullup(struct usb_gadget *_gadget, int is_on)
 {
 	struct ci_hdrc *ci = container_of(_gadget, struct ci_hdrc, gadget);
 
-	/* Data+ pullup controlled by OTG state machine in OTG fsm mode */
-	if (ci_otg_is_fsm_mode(ci))
+	/*
+	 * Data+ pullup controlled by OTG state machine in OTG fsm mode;
+	 * and don't touch Data+ in host mode for dual role config.
+	 */
+	if (ci_otg_is_fsm_mode(ci) || ci->role == CI_ROLE_HOST)
 		return 0;
 
 	pm_runtime_get_sync(&ci->gadget.dev);