usb: chipidea: otg: remove mutex unlock and lock while stop and start role

[ Upstream commit a5a356ce ]

Wrongly release mutex lock during otg_statemachine may result in re-enter
otg_statemachine, which is not allowed, we should do next state transtition
after previous one completed.

Fixes: 826cfe75 ("usb: chipidea: add OTG fsm operation functions implementation")
Cc: <stable@vger.kernel.org> # v3.16+
Signed-off-by: Li Jun <jun.li@freescale.com>
Signed-off-by: Peter Chen <peter.chen@freescale.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>

drivers/usb/chipidea/otg_fsm.c

@@ -537,7 +537,6 @@ static int ci_otg_start_host(struct otg_fsm *fsm, int on)
 {
 	struct ci_hdrc	*ci = container_of(fsm, struct ci_hdrc, fsm);
 
-	mutex_unlock(&fsm->lock);
 	if (on) {
 		ci_role_stop(ci);
 		ci_role_start(ci, CI_ROLE_HOST);
@@ -546,7 +545,6 @@ static int ci_otg_start_host(struct otg_fsm *fsm, int on)
 		hw_device_reset(ci, USBMODE_CM_DC);
 		ci_role_start(ci, CI_ROLE_GADGET);
 	}
-	mutex_lock(&fsm->lock);
 	return 0;
 }
 
@@ -554,12 +552,10 @@ static int ci_otg_start_gadget(struct otg_fsm *fsm, int on)
 {
 	struct ci_hdrc	*ci = container_of(fsm, struct ci_hdrc, fsm);
 
-	mutex_unlock(&fsm->lock);
 	if (on)
 		usb_gadget_vbus_connect(&ci->gadget);
 	else
 		usb_gadget_vbus_disconnect(&ci->gadget);
-	mutex_lock(&fsm->lock);
 
 	return 0;
 }