我在發(fā)INQUIRY命令時(shí),第三個(gè)階段(CSW)為什么一直返回NAK?下面是我的部分代碼 b_send_result = USB_ExHost_Ms_Send_Cmd(&g_Usb_Ex_HostMs.ms_cmd_data);
if(b_send_result == KAL_TRUE) { bReturn = USB_Host_Bulk_IN(temp_data,0x24/*,g_Usb_Ex_HostMs.ep_rx_num*/);//讀取的字節(jié)數(shù)可以大于真正返回的數(shù)據(jù),但不可小于 } else { bReturn = 0; dbg_print("Leave Inquiry ! USB_HOST_MS_RESULT_TIMEOUT \r\n"); } dbg_print("Inquiry is :"); for(i = 0;i < 0x24;i++) { sprintf(buf,"%02x ",temp_data[i]); dbg_print(buf); } dbg_print("\r\n"); USB_Host_Bulk_IN(CSW,13/*,g_Usb_Ex_HostMs.ep_rx_num*/);