>> >Does your UDC driver call composite_disconnect when disconnect from the host? >> >It should set all desc to NULL at related function ->disable. >> >> For ECM case, if ecm_set_alt() gets called with alt == 0, in_ep->desc and out_ep- >> >desc will be set up. But these two ep will not be enabled as gether_connect() is not >> executed. During disconnect from the host, ecm_disable() gets called with ep >> disabled. In this case, gether_disconnect() will not get called to set desc to NULL. >Would you please share your test case? I use Linux host, and the host will always set alt for 1, >and doesn't have this issue. Using Windows host (without any proprietary NCM/ECM driver installed) can reproduce set alt to 0. We just used Win10 to confirm this.