USB: fsl_qe_udc: Fix QE USB controller initialization

qe_udc_reg_init() leaves the USB controller enabled before muram memory
initialized. Sometimes the uninitialized muram memory confuses the
controller, and it start sending the busy interrupts.

Fix this by disabling the controller, it will be enabled later by
the gadget driver, at bind time.

Signed-off-by: Anton Vorontsov <avorontsov@ru.mvista.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 5 insertions, 1 deletions

diff --git a/drivers/usb/gadget/fsl_qe_udc.c b/drivers/usb/gadget/fsl_qe_udc.c
index 064582fb6a8..1319f8f7acb 100644
--- a/drivers/usb/gadget/fsl_qe_udc.c
+++ b/drivers/usb/gadget/fsl_qe_udc.c
@@ -2452,8 +2452,12 @@ static int __devinit qe_udc_reg_init(struct qe_udc *udc)
         struct usb_ctlr __iomem *qe_usbregs;
         qe_usbregs = udc->usb_regs;
 
-        /* Init the usb register */
+        /* Spec says that we must enable the USB controller to change mode. */
         out_8(&qe_usbregs->usb_usmod, 0x01);
+        /* Mode changed, now disable it, since muram isn't initialized yet. */
+        out_8(&qe_usbregs->usb_usmod, 0x00);
+
+        /* Initialize the rest. */
         out_be16(&qe_usbregs->usb_usbmr, 0);
         out_8(&qe_usbregs->usb_uscom, 0);
         out_be16(&qe_usbregs->usb_usber, USBER_ALL_CLEAR);