The patch below does not apply to the 3.0-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <sta...@kernel.org>.

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

>From 93e098a8fc02c579875e64001f7a511b7e75a16c Mon Sep 17 00:00:00 2001
From: John Stultz <john.stu...@linaro.org>
Date: Wed, 20 Jul 2011 17:09:34 -0700
Subject: [PATCH] usb: musb: fix oops on musb_gadget_pullup

an 'unhandled fault' is causes when a gadget driver calls
usb_gadget_connect() while the USB cable isn't plugged into
the OTG port.

the fault is caused by an access to MUSB's memory space
while its clock is turned off due to pm_runtime kicking
in.

in order to fix the fault, we enclose musb_gadget_pullup()
with pm_runtime_get_sync() ... pm_runtime_put() calls to
be sure we will always reach that path with clock turned on.

[ ba...@ti.com : simplified commit log; removed few things
        which didn't belong there ]

Cc: sta...@kernel.org
Reported-by: Zach Pfeffer <zach.pfef...@linaro.org>
Signed-off-by: John Stultz <john.stu...@linaro.org>
Signed-off-by: Felipe Balbi <ba...@ti.com>

diff --git a/drivers/usb/musb/musb_gadget.c b/drivers/usb/musb/musb_gadget.c
index b67a062..8c41a2e 100644
--- a/drivers/usb/musb/musb_gadget.c
+++ b/drivers/usb/musb/musb_gadget.c
@@ -1698,6 +1698,8 @@ static int musb_gadget_pullup(struct usb_gadget *gadget, 
int is_on)
 
        is_on = !!is_on;
 
+       pm_runtime_get_sync(musb->controller);
+
        /* NOTE: this assumes we are sensing vbus; we'd rather
         * not pullup unless the B-session is active.
         */
@@ -1707,6 +1709,9 @@ static int musb_gadget_pullup(struct usb_gadget *gadget, 
int is_on)
                musb_pullup(musb, is_on);
        }
        spin_unlock_irqrestore(&musb->lock, flags);
+
+       pm_runtime_put(musb->controller);
+
        return 0;
 }
 

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