MI 9 设备，执行一会usb自动断开，已经开启了自启动。

adbd 日志如下：

06-14 11:35:16.403 1965 1965 W NotificationService: Object died trying to show notification android.app.ITransientNotification$Stub$Proxy@670adbd in package com.netease.open.pocoservice
06-14 17:59:15.641 2293 2293 W /system/bin/adbd: type=1400 audit(0.0:241710): avc: denied { search } for comm=73796E6320737663203236 name="oem" dev="sde54" ino=59 scontext=u:r:adbd:s0 tcontext=u:object_r:oemfs:s0 tclass=dir permissive=0
06-14 18:00:45.494 2293 2293 I adbd : UsbFfs: offline
06-14 18:00:45.495 2293 2293 I adbd : ADB disconnect
06-14 18:00:45.496 2293 2293 I adbd : Calling send_auth_request...
06-14 18:00:45.503 2293 2293 I adbd : Loading keys from /data/misc/adb/adb_keys
06-14 18:00:45.505 2293 2293 I adbd : adb client authorized
06-14 18:26:35.521 2293 2293 I adbd : UsbFfs: offline
06-14 18:26:35.521 2293 2293 I adbd : ADB disconnect
06-14 18:26:35.522 2293 2293 I adbd : Calling send_auth_request...
06-14 18:26:35.527 2293 2293 I adbd : Loading keys from /data/misc/adb/adb_keys
06-14 18:26:35.529 2293 2293 I adbd : adb client authorized
06-14 18:39:48.943 2293 10131 I adbd : USB event: FUNCTIONFS_SUSPEND
06-14 18:39:49.040 2293 10131 I adbd : USB event: FUNCTIONFS_DISABLE
06-14 18:39:49.042 2293 10667 I adbd : UsbFfs: connection terminated: read 4737 failed with error Cannot send after transport endpoint shutdown
06-14 18:39:49.043 2293 2293 I adbd : UsbFfs: offline
06-14 18:39:49.044 2293 2293 I adbd : ADB disconnect
06-14 18:39:49.044 2293 2293 I adbd : destroying transport UsbFfs
06-14 18:39:49.044 2293 2293 I adbd : UsbFfsConnection being destroyed
06-14 18:39:49.257 2293 2303 I adbd : opening control endpoint /dev/usb-ffs/adb/ep0
06-14 18:39:49.262 2293 2303 I adbd : UsbFfsConnection constructed
06-14 18:39:49.262 2293 15215 I adbd : USB event: FUNCTIONFS_BIND
06-14 18:48:00.610 2293 15215 I adbd : USB event: FUNCTIONFS_ENABLE
06-14 18:48:01.662 2293 2293 I adbd : UsbFfs: already offline
06-14 18:48:01.662 2293 2293 I adbd : Calling send_auth_request...
06-14 18:48:01.666 2293 2293 I adbd : Loading keys from /data/misc/adb/adb_keys
06-14 18:48:01.666 2293 2293 I adbd : adb client authorized
06-14 18:50:49.635 2293 15215 I adbd : USB event: FUNCTIONFS_SUSPEND
06-14 18:50:49.661 2293 15215 I adbd : USB event: FUNCTIONFS_DISABLE
06-14 18:50:49.667 2293 15477 I adbd : UsbFfs: connection terminated: read 187 failed with error Cannot send after transport endpoint shutdown
06-14 18:50:49.668 2293 2293 I adbd : UsbFfs: offline
06-14 18:50:49.668 2293 2293 I adbd : ADB disconnect
06-14 18:50:49.668 2293 2293 I adbd : destroying transport UsbFfs
06-14 18:50:49.670 2293 2293 I adbd : UsbFfsConnection being destroyed
06-14 18:50:49.813 2293 2303 I adbd : opening control endpoint /dev/usb-ffs/adb/ep0
06-14 18:50:49.816 2293 2303 I adbd : UsbFfsConnection constructed
06-14 18:50:49.816 2293 16548 I adbd : USB event: FUNCTIONFS_BIND
06-14 18:53:43.910 2293 16548 I adbd : USB event: FUNCTIONFS_ENABLE
06-14 18:53:44.131 2293 2293 I adbd : UsbFfs: already offline
06-14 18:53:44.131 2293 2293 I adbd : Calling send_auth_request...
06-14 18:53:44.135 2293 2293 I adbd : Loading keys from /data/misc/adb/adb_keys
06-14 18:53:44.135 2293 2293 I adbd : adb client authorized
06-14 18:57:27.504 2293 16548 I adbd : USB event: FUNCTIONFS_SUSPEND
06-14 18:57:27.538 2293 16548 I adbd : USB event: FUNCTIONFS_DISABLE
06-14 18:57:27.541 2293 16797 I adbd : UsbFfs: connection terminated: read 347 failed with error Cannot send after transport endpoint shutdown
06-14 18:57:27.541 2293 2293 I adbd : UsbFfs: offline
06-14 18:57:27.542 2293 2293 I adbd : ADB disconnect
06-14 18:57:27.542 2293 2293 I adbd : destroying transport UsbFfs
06-14 18:57:27.542 2293 2293 I adbd : UsbFfsConnection being destroyed
06-14 18:57:27.695 2293 2303 I adbd : opening control endpoint /dev/usb-ffs/adb/ep0
06-14 18:57:27.697 2293 2303 I adbd : UsbFfsConnection constructed
06-14 18:57:27.699 2293 16874 I adbd : USB event: FUNCTIONFS_BIND
06-14 19:03:09.929 2293 16874 I adbd : USB event: FUNCTIONFS_ENABLE
06-14 19:03:10.176 2293 2293 I adbd : UsbFfs: already offline
06-14 19:03:10.176 2293 2293 I adbd : Calling send_auth_request...
06-14 19:03:10.179 2293 2293 I adbd : Loading keys from /data/misc/adb/adb_keys
06-14 19:03:10.179 2293 2293 I adbd : adb client authorized
06-14 19:06:47.651 2293 16874 I adbd : USB event: FUNCTIONFS_SUSPEND
06-14 19:06:47.685 2293 16874 I adbd : USB event: FUNCTIONFS_DISABLE
06-14 19:06:47.686 2293 16932 I adbd : UsbFfs: connection terminated: read 258 failed with error Cannot send after transport endpoint shutdown
06-14 19:06:47.686 2293 2293 I adbd : UsbFfs: offline
06-14 19:06:47.686 2293 2293 I adbd : ADB disconnect
06-14 19:06:47.686 2293 2293 I adbd : destroying transport UsbFfs
06-14 19:06:47.686 2293 2293 I adbd : UsbFfsConnection being destroyed
06-14 19:06:47.845 2293 2303 I adbd : opening control endpoint /dev/usb-ffs/adb/ep0
06-14 19:06:47.850 2293 2303 I adbd : UsbFfsConnection constructed
06-14 19:06:47.854 2293 16976 I adbd : USB event: FUNCTIONFS_BIND
06-14 19:18:34.860 2293 16976 I adbd : USB event: FUNCTIONFS_ENABLE
06-14 19:18:35.346 2293 2293 I adbd : UsbFfs: already offline
06-14 19:18:35.346 2293 2293 I adbd : Calling send_auth_request...
06-14 19:18:35.349 2293 2293 I adbd : Loading keys from /data/misc/adb/adb_keys