[3.16.y-ckt stable] Patch "usb: common: otg-fsm: only signal connect after switching to peripheral" 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: common: otg-fsm: only signal connect after switching to peripheral

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?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.16.y-queue

This patch is scheduled to be released in version 3.16.7-ckt10.

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 6dca3f57c530b507468a9c12433d630db20874c6 Mon Sep 17 00:00:00 2001
From: Peter Chen <peter.chen at freescale.com>
Date: Thu, 12 Mar 2015 09:47:53 +0800
Subject: usb: common: otg-fsm: only signal connect after switching to
 peripheral

commit a886bd92267c9e3d5c912860c6fb5a68479a7643 upstream.

We should signal connect (pull up dp) after we have already
at peripheral mode, otherwise, the dp may be toggled due to
we reset controller or do disconnect during the initialization
for peripheral, then, the host may be confused during the
enumeration, eg, it finds the reset can't succeed, but the
device is still there, see below error message.

hub 1-0:1.0: USB hub found
hub 1-0:1.0: 1 port detected
hub 1-0:1.0: cannot reset port 1 (err = -32)
hub 1-0:1.0: cannot reset port 1 (err = -32)
hub 1-0:1.0: cannot reset port 1 (err = -32)
hub 1-0:1.0: cannot reset port 1 (err = -32)
hub 1-0:1.0: cannot reset port 1 (err = -32)
hub 1-0:1.0: Cannot enable port 1.  Maybe the USB cable is bad?
hub 1-0:1.0: cannot reset port 1 (err = -32)
hub 1-0:1.0: cannot reset port 1 (err = -32)
hub 1-0:1.0: cannot reset port 1 (err = -32)
hub 1-0:1.0: cannot reset port 1 (err = -32)
hub 1-0:1.0: cannot reset port 1 (err = -32)
hub 1-0:1.0: Cannot enable port 1.  Maybe the USB cable is bad?
hub 1-0:1.0: cannot reset port 1 (err = -32)
hub 1-0:1.0: cannot reset port 1 (err = -32)
hub 1-0:1.0: cannot reset port 1 (err = -32)
hub 1-0:1.0: cannot reset port 1 (err = -32)
hub 1-0:1.0: cannot reset port 1 (err = -32)
hub 1-0:1.0: Cannot enable port 1.  Maybe the USB cable is bad?
hub 1-0:1.0: cannot reset port 1 (err = -32)
hub 1-0:1.0: cannot reset port 1 (err = -32)
hub 1-0:1.0: cannot reset port 1 (err = -32)
hub 1-0:1.0: cannot reset port 1 (err = -32)
hub 1-0:1.0: cannot reset port 1 (err = -32)
hub 1-0:1.0: Cannot enable port 1.  Maybe the USB cable is bad?
hub 1-0:1.0: unable to enumerate USB device on port 1

Fixes: the issue existed when the otg fsm code was added.
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/common/usb-otg-fsm.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/usb/common/usb-otg-fsm.c b/drivers/usb/common/usb-otg-fsm.c
index 98e8340a5bb1..c812fefe0e50 100644
--- a/drivers/usb/common/usb-otg-fsm.c
+++ b/drivers/usb/common/usb-otg-fsm.c
@@ -150,9 +150,9 @@ static int otg_set_state(struct otg_fsm *fsm, enum usb_otg_state new_state)
 		break;
 	case OTG_STATE_B_PERIPHERAL:
 		otg_chrg_vbus(fsm, 0);
-		otg_loc_conn(fsm, 1);
 		otg_loc_sof(fsm, 0);
 		otg_set_protocol(fsm, PROTO_GADGET);
+		otg_loc_conn(fsm, 1);
 		break;
 	case OTG_STATE_B_WAIT_ACON:
 		otg_chrg_vbus(fsm, 0);
@@ -213,10 +213,10 @@ static int otg_set_state(struct otg_fsm *fsm, enum usb_otg_state new_state)

 		break;
 	case OTG_STATE_A_PERIPHERAL:
-		otg_loc_conn(fsm, 1);
 		otg_loc_sof(fsm, 0);
 		otg_set_protocol(fsm, PROTO_GADGET);
 		otg_drv_vbus(fsm, 1);
+		otg_loc_conn(fsm, 1);
 		otg_add_timer(fsm, A_BIDL_ADIS);
 		break;
 	case OTG_STATE_A_WAIT_VFALL: