Commit 72c487df authored Jul 20, 2011 by John Stultz Committed by Felipe Balbi Aug 01, 2011

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.

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

Cc: stable@kernel.org
Reported-by: Zach Pfeffer <zach.pfeffer@linaro.org>
Signed-off-by: John Stultz <john.stultz@linaro.org>
Signed-off-by: Felipe Balbi <balbi@ti.com>

parent d4aefec5

drivers/usb/musb/musb_gadget.c

+5 −0

Original line number	Diff line number	Diff line
		@@ -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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