Hi, >> >> is it this code? i will remove the redundant code after complete. >> >> >> >> ka_ep_p->req.complete(&ka_ep_p->ep, &req->req); >> >> if (num == 0) { >> >> ka_ep_p->req.length = 0; >> >> usb_ep_queue(&ka_ep_p->ep, &req->req, 0); >> >> ka_ep_p->desc = &ep0_in_desc; >> >> } >> > >> > you should delete the request from your list. Whatever you do, has to be >> > undone. >> >> got it. i add list_del_init() to delete the request from the list. > > _init() is unnecessary > >> >> >> i read the net2272.c, the net2272_enable() is called by gadget driver >> >> enable_endpoint(). When i run the gadget driver, enable_endpoint() is >> >> called for fsg->bulk_in and fsg->bulk_out. The enable_endpoint() of >> >> fsg->intr_in is not called because transport_is_cbi() is false. So >> >> how can the endpoint 0 be enabled? >> > >> > endpoint 0 has to be always enabled by the UDC driver. Gadget driver >> > expects endpoint 0 to be ready. >> >> i read through the net2272.c, i do not see where the endpoint 0 is >> enabled. I blindly enable my endpoint zero. i think my code is wrong. >> kagen2_ep_enable(&ka_ep->ep, &ep0_in_desc); >> kagen2_ep_enable(&ka_ep->ep, &ep0_out_desc); > > yeah, you need to enabled it during driver initialization In the udc driver, i can't assign a single ep0 descriptor to both ep0_in_desc and ep0_out_desc. i think i should skip ep0_out_desc. Bear in mind that i only define 3 endpoints in udc driver: ep0, ep1 bulk in, ep1 bulk out. Will it cause any problem to gadget driver? thanks, victor -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html