USB: ohci-at91: add a reset function to fix race condition
authorNicolas Ferre <nicolas.ferre@atmel.com>
Wed, 9 May 2012 08:48:54 +0000 (10:48 +0200)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Wed, 9 May 2012 22:22:27 +0000 (15:22 -0700)
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>
Cc: stable <stable@vger.kernel.org>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
drivers/usb/host/ohci-at91.c

index d4608c2d5b64bb584bd81fa3f4155b05790cae3f..a665b3eaa74672f28e7d011b1ea4da265667187f 100644 (file)
@@ -223,7 +223,7 @@ static void __devexit 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);
@@ -233,6 +233,14 @@ 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) {
                dev_err(hcd->self.controller, "can't start %s\n",
@@ -419,6 +427,7 @@ 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,