USB: ohci-at91: add a reset function to fix race condition

commit 07e4e556 upstream.

A possible race condition appears because we are not initializing
the ohci->regs before calling usb_hcd_request_irqs().
We move the call to ohci_init() in hcd->driver->reset() instead of
hcd->driver->start() to fix this.
This was experienced when we share the same IRQ line between OHCI and EHCI
controllers.
Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Tested-by: Christian Eggers <christian.eggers@kathrein.de>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

drivers/usb/host/ohci-at91.c

@@ -199,7 +199,7 @@ static void usb_hcd_at91_remove(struct usb_hcd *hcd,
 /*-------------------------------------------------------------------------*/
 
 static int __devinit
-ohci_at91_start (struct usb_hcd *hcd)
+ohci_at91_reset (struct usb_hcd *hcd)
 {
 	struct at91_usbh_data	*board = hcd->self.controller->platform_data;
 	struct ohci_hcd		*ohci = hcd_to_ohci (hcd);
@@ -209,6 +209,14 @@ ohci_at91_start (struct usb_hcd *hcd)
 		return ret;
 
 	ohci->num_ports = board->ports;
+	return 0;
+}
+
+static int __devinit
+ohci_at91_start (struct usb_hcd *hcd)
+{
+	struct ohci_hcd		*ohci = hcd_to_ohci (hcd);
+	int			ret;
 
 	if ((ret = ohci_run(ohci)) < 0) {
 		err("can't start %s", hcd->self.bus_name);
@@ -390,6 +398,7 @@ static const struct hc_driver ohci_at91_hc_driver = {
 	/*
 	 * basic lifecycle operations
 	 */
+	.reset =		ohci_at91_reset,
 	.start =		ohci_at91_start,
 	.stop =			ohci_stop,
 	.shutdown =		ohci_shutdown,