[PATCH] USB: ohci-at91: add a reset function to fix race condition
Alan Stern
stern at rowland.harvard.edu
Wed May 9 13:45:35 EDT 2012
On Wed, 9 May 2012, Nicolas Ferre wrote:
> 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 at atmel.com>
> Tested-by: Christian Eggers <christian.eggers at kathrein.de>
> Cc: stable <stable at vger.kernel.org>
Acked-by: Alan Stern <stern at rowland.harvard.edu>
> ---
> drivers/usb/host/ohci-at91.c | 11 ++++++++++-
> 1 file changed, 10 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/usb/host/ohci-at91.c b/drivers/usb/host/ohci-at91.c
> index 13ebeca..55d3d64 100644
> --- a/drivers/usb/host/ohci-at91.c
> +++ b/drivers/usb/host/ohci-at91.c
> @@ -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) {
> err("can't start %s", hcd->self.bus_name);
> @@ -418,6 +426,7 @@ 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,
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