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

[Eric Nelson <eric.nelson@boundarydevices.com>]

Thanks Stephen,

On 06/23/2014 11:02 AM, Stephen Warren wrote:
> 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.
> 

Tested-by: Eric Nelson <eric.nelson@boundarydevices.com>

Tested on Nitrogen6x (i.MX6). On this platform, without the patch, I
could execute ping exactly once.

With the patch, repeated pings work great!

Regards,


Eric