[4.2.y-ckt stable] Patch "usb: chipidea: debug: disable usb irq while role switch" has been added to staging queue

[Kamal Mostafa]

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

    usb: chipidea: debug: disable usb irq while role switch

to the linux-4.2.y-queue branch of the 4.2.y-ckt extended stable tree 
which can be found at:

    http://kernel.ubuntu.com/git/ubuntu/linux.git/log/?h=linux-4.2.y-queue

This patch is scheduled to be released in version 4.2.8-ckt2.

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

For more information about the 4.2.y-ckt tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Kamal

---8<------------------------------------------------------------

>From d0321b60b4ff0c78b2510ed415e75244aa2ef8e5 Mon Sep 17 00:00:00 2001
From: Li Jun <jun.li at freescale.com>
Date: Tue, 13 Oct 2015 18:23:31 +0800
Subject: usb: chipidea: debug: disable usb irq while role switch

commit 251b3c8b57481bcecd3f753108e36e7389ce12ac upstream.

Since the ci->role will be set after the host role start is complete, there
will be nobody cared irq during start host if usb irq enabled. This error
can be reproduced on i.mx6 sololite EVK board by:
1. disable otg id irq(IDIE) and disable all real otg properties of usbotg1
   in dts.
2. boot up the board with ID cable and usb device connected.
3. echo gadget > /sys/kernel/debug/ci_hdrc.0/role
4. echo host > /sys/kernel/debug/ci_hdrc.0/role
5. irq 212: nobody cared.

Signed-off-by: Li Jun <jun.li at freescale.com>
Signed-off-by: Peter Chen <peter.chen at freescale.com>
Signed-off-by: Kamal Mostafa <kamal at canonical.com>
---
 drivers/usb/chipidea/debug.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/usb/chipidea/debug.c b/drivers/usb/chipidea/debug.c
index 5b7061a..6a4151c 100644
--- a/drivers/usb/chipidea/debug.c
+++ b/drivers/usb/chipidea/debug.c
@@ -316,8 +316,10 @@ static ssize_t ci_role_write(struct file *file, const char __user *ubuf,
 	if (role == CI_ROLE_END || role == ci->role)
 		return -EINVAL;

+	disable_irq(ci->irq);
 	ci_role_stop(ci);
 	ret = ci_role_start(ci, role);
+	enable_irq(ci->irq);

 	return ret ? ret : count;
 }
--
1.9.1