[U-Boot] [PATCH] usb: ci_udc: fix interaction with CONFIG_USB_ETH_CDC

[Marek Vasut <marex@denx.de>]

On Monday, June 23, 2014 at 08:02:48 PM, Stephen Warren wrote:

+CC Jorg, rest of email is intact. Jorg, does this patch fix your issue?

> From: Stephen Warren <swarren@nvidia.com>
> 
> ci_udc.c's usb_gadget_unregister_driver() doesn't call driver->unbind()
> unlike other USB gadget drivers. Fix it to do this.
> 
> Without this, when ether.c's CDC Ethernet device is torn down,
> eth_unbind() is never called, so dev->gadget is never set to NULL.
> For some reason, usb_eth_halt() is called both at the end of the first
> use of the Ethernet device, and prior to any subsequent use. Since
> dev->gadget is never cleared, all calls to usb_eth_halt() attempt to
> stop, disconnect, and clean up the device, resulting in double cleanup,
> which hangs U-Boot on my Tegra device at least.
> 
> ci_udc allocates its own singleton EP0 request object, and cleans it up
> during usb_gadget_unregister_driver(). This appears necessary when using
> the USB gadget framework in U-Boot, since that does not allocate/free
> the EP0 request. However, the CDC Ethernet driver *does* allocate and
> free its own EP0 requests. Consequently, we must protect
> ci_ep_free_request() against double-freeing the request.
> 
> Signed-off-by: Stephen Warren <swarren@nvidia.com>
> ---
>  drivers/usb/gadget/ci_udc.c | 8 +++++++-
>  1 file changed, 7 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/usb/gadget/ci_udc.c b/drivers/usb/gadget/ci_udc.c
> index b18bee43ad89..c3f6467b7db4 100644
> --- a/drivers/usb/gadget/ci_udc.c
> +++ b/drivers/usb/gadget/ci_udc.c
> @@ -226,8 +226,11 @@ static void ci_ep_free_request(struct usb_ep *ep,
> struct usb_request *req) int num;
> 
>  	num = ci_ep->desc->bEndpointAddress & USB_ENDPOINT_NUMBER_MASK;
> -	if (num == 0)
> +	if (num == 0) {
> +		if (!controller.ep0_req)
> +			return;
>  		controller.ep0_req = 0;
> +	}
> 
>  	if (ci_req->b_buf)
>  		free(ci_req->b_buf);
> @@ -909,6 +912,9 @@ int usb_gadget_unregister_driver(struct
> usb_gadget_driver *driver) {
>  	udc_disconnect();
> 
> +	driver->unbind(&controller.gadget);
> +	controller.driver = NULL;
> +
>  	ci_ep_free_request(&controller.ep[0].ep, &controller.ep0_req->req);
>  	free(controller.items_mem);
>  	free(controller.epts);

Best regards,
Marek Vasut