android studio 连不上真机

不是占用端口号的问题
下面是错误日志,坐等大虾
Unable to obtain debug bridge
java.util.concurrent.CancellationException
at com.android.tools.idea.ddms.adb.AdbService$BridgeConnectorTask.run(AdbService.java:182)
at com.intellij.openapi.application.impl.ApplicationImpl$8.run(ApplicationImpl.java:419)
at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:471)
at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:334)
at java.util.concurrent.FutureTask.run(FutureTask.java:166)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1110)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:603)
at java.lang.Thread.run(Thread.java:722)
at com.intellij.openapi.application.impl.ApplicationImpl$1$1.run(ApplicationImpl.java:149)