[3.16.y-ckt stable] Patch "usb: chipidea: otg: remove mutex unlock and lock while stop and start role" has been added to staging queue

[Luis Henriques]

This is a note to let you know that I have just added a patch titled

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

to the linux-3.16.y-queue branch of the 3.16.y-ckt extended stable tree 
which can be found at:

    http://kernel.ubuntu.com/git/ubuntu/linux.git/log/?h=linux-3.16.y-queue

This patch is scheduled to be released in version 3.16.7-ckt12.

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.16.y-ckt tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Luis

------

>From a3cc6af44385014d990aec5216af40f13e0fda87 Mon Sep 17 00:00:00 2001
From: Li Jun <jun.li at freescale.com>
Date: Sun, 12 Apr 2015 17:51:02 +0800
Subject: usb: chipidea: otg: remove mutex unlock and lock while stop and start
 role

commit a5a356cee89f86ff86cc3ce24136ca1f802c1bf1 upstream.

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: 826cfe751f3e ("usb: chipidea: add OTG fsm operation functions implementation")
Signed-off-by: Li Jun <jun.li at freescale.com>
Signed-off-by: Peter Chen <peter.chen at freescale.com>
Signed-off-by: Greg Kroah-Hartman <gregkh at linuxfoundation.org>
Signed-off-by: Luis Henriques <luis.henriques at canonical.com>
---
 drivers/usb/chipidea/otg_fsm.c | 4 ----
 1 file changed, 4 deletions(-)

diff --git a/drivers/usb/chipidea/otg_fsm.c b/drivers/usb/chipidea/otg_fsm.c
index caaabc58021e..34a52cd7bfb7 100644
--- a/drivers/usb/chipidea/otg_fsm.c
+++ b/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;
 }