Hi Vitaly,
On Sat, Nov 27, 2010 at 2:23 AM, Vitaly Kuzmichev vkuzmichev@mvista.com wrote:
Hi Lei,
Lei Wen wrote:
Since the ether may not be the only one usb gadget would be used in the uboot, it is neccessary to do the register each time the eth begin to work to make usb gadget driver less confussed when we want to use two different usb gadget at the same time. [...] @@ -1788,6 +1788,8 @@ static int usb_eth_init(struct eth_device *netdev, bd_t *bd) error("received NULL ptr"); goto fail; }
- if (usb_gadget_register_driver(ð_driver) < 0)
- goto fail;
You probably need then at least to remove usb_gadget_register_driver call from usb_eth_initialize. And add usb_gadget_unregister_driver in usb_eth_halt.
I am afraid that remove usb_gadget_register_driver call from usb_eth_initialize is not possible. For tftp as example, it would call eth_halt before the eth_init. If we do the remove behavior, the gadget still not valid yet in the first eth_halt call which would cause the uboot becomes halt.
For example, my UDC driver returns EBUSY if another gadget driver tries to register itself. (Yes, I do not want to have more than 1 gadget). With your patch the gadget driver will fail each time when initializing. Anyway if I "fix" my UDC driver some day the Ether gadget will try to register itself twice (and more times later). So I will have to protect it against this bad behavior.
Two gadget example may comes from what I am using now. I am current attempting to make the tftp and fastboot cowork togetther. Since fastboot is a cool tool, I think people may want it beside they still use the tftp. Would that be enough convincing?:)
I think the gadget driver should adopt like this to allow two gadget coexist. And from gadget driver's review, the switch from one gadget to another is easy, just register it to another should be enough. Does it really need to return EBUSY?
Best regards, Lei