[Sony Xperia S, Acro S, Ion] schickel:
Here is a "small" logcat after activating wifi-hotspot:

10-18 08:09:13.287 D/StatusBar.NetworkController(654): refreshViews: Data not connected!! Set no data type icon
10-18 08:09:13.287 D/StatusBar.NetworkController(654): refreshViews connected={ wifi } level=4 combinedSignalIconId=0x7f0200c0/com.android.systemui:drawable/stat_sys_wifi_signal_3_fully combinedActivityIconId=0x0 mobileLabel=Vodafone.de wifiLabel=OWLxxxxXXXXxxxxXXXX emergencyOnly=false combinedLabel=OWLxxxxXXXXxxxxXXXX mAirplaneMode=false mDataActivity=0 mPhoneSignalIconId=0x7f0200a8 mDataDirectionIconId=0x0 mDataSignalIconId=0x7f0200a8 mDataTypeIconId=0x0 mNoSimIconId=0x0 mWifiIconId=0x7f0200c0 mBluetoothTetherIconId=0x10808c3
10-18 08:09:13.287 D/StatusBar.NetworkController(654): changing data overlay icon id to 0
10-18 08:09:13.337 D/StatusBar.NetworkController(654): refreshViews: Data not connected!! Set no data type icon
10-18 08:09:13.337 D/StatusBar.NetworkController(654): refreshViews connected={ wifi } level=4 combinedSignalIconId=0x7f0200c2/com.android.systemui:drawable/stat_sys_wifi_signal_4_fully combinedActivityIconId=0x0 mobileLabel=Vodafone.de wifiLabel=OWLxxxxXXXXxxxxXXXX emergencyOnly=false combinedLabel=OWLxxxxXXXXxxxxXXXX mAirplaneMode=false mDataActivity=0 mPhoneSignalIconId=0x7f0200a8 mDataDirectionIconId=0x0 mDataSignalIconId=0x7f0200a8 mDataTypeIconId=0x0 mNoSimIconId=0x0 mWifiIconId=0x7f0200c2 mBluetoothTetherIconId=0x10808c3
10-18 08:09:13.877 I/ActivityManager(507): START {flg=0x10000000 cmp=com.android.systemui/com.sonymobile.systemui.statusbar.tools.TetheringDialogDummyActivity u=0} from pid 654
10-18 08:09:14.007 I/ActivityManager(507): START {act=com.sonymobile.intent.action.TETHER_CONFIRMATION_DIALOG cmp=com.android.systemui/com.sonymobile.systemui.statusbar.tools.TetherConfirmationDialog u=0} from pid 654
10-18 08:09:14.177 D/WifiService(507): setWifiEnabled: false pid=654, uid=10134
10-18 08:09:14.177 D/BackupManagerService(507): Now staging backup of com.android.providers.settings
10-18 08:09:14.207 D/ConnectivityService(507): ConnectivityChange for WIFI: DISCONNECTED/DISCONNECTED
10-18 08:09:14.227 D/ConnectivityService(507): Attempting to switch to mobile
10-18 08:09:14.227 D/ConnectivityService(507): Attempting to switch to BLUETOOTH_TETHER
10-18 08:09:14.227 D/ConnectivityService(507): handleConnectivityChange: changed linkProperty[1]: doReset=true resetMask=3
10-18 08:09:14.227 D/ConnectivityService(507): curLp=InterfaceName: wlan0 LinkAddresses: [192.168.100.91/24,] Routes: [0.0.0.0/0 -> 192.168.100.3,] DnsAddresses: [194.25.0.60,] HttpProxy: [ProxyProperties.mHost == null]
10-18 08:09:14.227 D/ConnectivityService(507): newLp= null
10-18 08:09:14.237 D/ConnectivityService(507): Routes in main table - [ [0.0.0.0/0 -> 192.168.100.3, 192.168.100.3/32 -> 0.0.0.0, 194.25.0.60/32 -> 192.168.100.3] ]
10-18 08:09:14.237 D/ConnectivityService(507): not removing 192.168.100.3/32 -> 0.0.0.0 as it's still in use
10-18 08:09:14.237 D/ConnectivityService(507): Routes in main table - [ [192.168.100.3/32 -> 0.0.0.0, 194.25.0.60/32 -> 192.168.100.3] ]
10-18 08:09:14.237 D/ConnectivityService(507): Removing 0.0.0.0/0 -> 192.168.100.3 for interface wlan0
[B][COLOR="Red"]10-18 08:09:14.237 E/ConnectivityService(507): Exception trying to remove a route: java.lang.IllegalStateException: command '212 interface route remove wlan0 default 0.0.0.0 0 192.168.100.3' failed with '400 212 Failed to remove route from default table (No such process)'[/COLOR][/B]
10-18 08:09:14.237 D/ConnectivityService(507): Removing src route for:192.168.100.91
10-18 08:09:14.277 D/StatusBar.NetworkController(654): refreshViews: Data not connected!! Set no data type icon
10-18 08:09:14.277 D/StatusBar.NetworkController(654): refreshViews connected={ } level=4 combinedSignalIconId=0x7f0200a8/com.android.systemui:drawable/stat_sys_signal_4_fully combinedActivityIconId=0x0 mobileLabel=Vodafone.de wifiLabel= emergencyOnly=false combinedLabel=Vodafone.de mAirplaneMode=false mDataActivity=0 mPhoneSignalIconId=0x7f0200a8 mDataDirectionIconId=0x0 mDataSignalIconId=0x7f0200a8 mDataTypeIconId=0x0 mNoSimIconId=0x0 mWifiIconId=0x7f0200c3 mBluetoothTetherIconId=0x10808c3
10-18 08:09:14.277 D/StatusBar.NetworkController(654): refreshViews: Data not connected!! Set no data type icon
10-18 08:09:14.307 D/StatusBar.NetworkController(654): refreshViews connected={ } level=4 combinedSignalIconId=0x7f0200a8/com.android.systemui:drawable/stat_sys_signal_4_fully combinedActivityIconId=0x0 mobileLabel=Vodafone.de wifiLabel= emergencyOnly=false combinedLabel=Vodafone.de mAirplaneMode=false mDataActivity=0 mPhoneSignalIconId=0x7f0200a8 mDataDirectionIconId=0x0 mDataSignalIconId=0x7f0200a8 mDataTypeIconId=0x0 mNoSimIconId=0x0 mWifiIconId=0x0 mBluetoothTetherIconId=0x10808c3
10-18 08:09:14.317 D/ConnectivityService(507): Routes in main table - [ [194.25.0.60/32 -> 192.168.100.3] ]
10-18 08:09:14.317 D/ConnectivityService(507): Removing 192.168.100.3/32 -> 0.0.0.0 for interface wlan0
[B][COLOR="red"]10-18 08:09:14.317 E/ConnectivityService(507): Exception trying to remove a route: java.lang.IllegalStateException: command '214 interface route remove wlan0 default 192.168.100.3 32 0.0.0.0' failed with '400 214 Failed to remove route from default table (No such process)'[/COLOR][/B]
10-18 08:09:14.317 D/ConnectivityService(507): Routes in main table - [ [] ]
10-18 08:09:14.317 D/ConnectivityService(507): Removing 194.25.0.60/32 -> 192.168.100.3 for interface wlan0
[B][COLOR="red"]10-18 08:09:14.327 E/ConnectivityService(507): Exception trying to remove a route: java.lang.IllegalStateException: command '215 interface route remove wlan0 default 194.25.0.60 32 192.168.100.3' failed with '400 215 Failed to remove route from default table (No such process)'[/COLOR][/B]
10-18 08:09:14.327 D/ConnectivityService(507): resetConnections(wlan0, 3)
10-18 08:09:14.327 I/ActivityManager(507): Start proc com.google.android.keep for broadcast com.google.android.keep/.notification.AlertReceiver: pid=8533 uid=10210 gids={3003, 1015, 1023, 1028}
10-18 08:09:14.387 W/InputMethodManagerService(507): Window already focused, ignoring focus gain of: com.android.internal.view.IInputMethodClient$Stub$Proxy@4180b170 attribute=null
10-18 08:09:14.397 D/PhoneStatusBar(654): disable: < expand icons alerts ticker* system_info back home recent clock >
10-18 08:09:14.497 D/ConnectivityService(507): resetting DNS cache for wlan0
10-18 08:09:14.507 D/ConnectivityService(507): sendStickyBroadcast: action=android.net.conn.CONNECTIVITY_CHANGE_IMMEDIATE
10-18 08:09:14.507 D/ConnectivityService(507): sendStickyBroadcastDelayed: delayMs=3000, action=android.net.conn.CONNECTIVITY_CHANGE
10-18 08:09:14.507 D/ConnectivityService(507): ConnectivityChange for WIFI: DISCONNECTED/DISCONNECTED
10-18 08:09:14.507 D/ConnectivityService(507): Attempting to switch to mobile
10-18 08:09:14.517 D/ConnectivityService(507): Attempting to switch to BLUETOOTH_TETHER
10-18 08:09:14.517 D/ConnectivityService(507): handleConnectivityChange: changed linkProperty[1]: doReset=true resetMask=3
10-18 08:09:14.517 D/ConnectivityService(507): curLp=null
10-18 08:09:14.517 D/ConnectivityService(507): newLp= null
10-18 08:09:14.517 D/ConnectivityService(507): resetConnections(wlan0, 3)
10-18 08:09:14.607 D/ConnectivityService(507): reportNetworkCondition(1, 0)
10-18 08:09:14.627 D/ConnectivityService(507): sendStickyBroadcast: action=android.net.conn.CONNECTIVITY_CHANGE_IMMEDIATE
10-18 08:09:14.647 D/ConnectivityService(507): sendStickyBroadcastDelayed: delayMs=3000, action=android.net.conn.CONNECTIVITY_CHANGE
10-18 08:09:14.647 D/ConnectivityService(507): ConnectivityChange for mobile: CONNECTING/CONNECTING
10-18 08:09:14.647 D/ConnectivityService(507): handleInetConditionChange: no active default network - ignore
10-18 08:09:14.777 D/StatusBar.NetworkController(654): refreshViews: Data not connected!! Set no data type icon
10-18 08:09:14.777 D/StatusBar.NetworkController(654): refreshViews connected={ } level=4 combinedSignalIconId=0x7f0200a8/com.android.systemui:drawable/stat_sys_signal_4_fully combinedActivityIconId=0x0 mobileLabel=Vodafone.de wifiLabel= emergencyOnly=false combinedLabel=Vodafone.de mAirplaneMode=false mDataActivity=0 mPhoneSignalIconId=0x7f0200a8 mDataDirectionIconId=0x0 mDataSignalIconId=0x7f0200a8 mDataTypeIconId=0x0 mNoSimIconId=0x0 mWifiIconId=0x0 mBluetoothTetherIconId=0x10808c3
10-18 08:09:14.837 I/ActivityManager(507): Start proc com.sonyericsson.tetherentitlementcheck for broadcast com.sonyericsson.tetherentitlementcheck/.TetheringMobileStateReceiver: pid=8555 uid=10135 gids={1028}
10-18 08:09:14.907 I/ActivityManager(507): No longer want com.touchtype.swiftkey (pid 7677): hidden #16
10-18 08:09:14.937 I/ActivityManager(507): No longer want com.sonyericsson.provider.voipcalllog (pid 6899): hidden #16
10-18 08:09:15.397 D/PhoneStatusBar(654): addNotification score=0
10-18 08:09:16.547 D/StatusBar.NetworkController(654): onSignalStrengthsChanged signalStrength=SignalStrength: 9 255 -120 -160 -120 -1 8 99 2147483647 2147483647 2147483647 2147483647 2147483647 gsm|lte level=3
10-18 08:09:16.587 D/ConnectivityService(507): ConnectivityChange for mobile: CONNECTED/CONNECTED
10-18 08:09:16.587 D/ConnectivityService(507): Setting TCP values: [4094,87380,1220608,4096,16384,1220608] which comes from [net.tcp.buffersize.hsdpa]
10-18 08:09:16.587 D/ConnectivityService(507): adding dns 139.7.30.126 for mobile
10-18 08:09:16.587 D/ConnectivityService(507): adding dns 139.7.30.125 for mobile
10-18 08:09:16.607 D/ConnectivityService(507): handleConnectivityChange: changed linkProperty[0]: doReset=false resetMask=0
10-18 08:09:16.607 D/ConnectivityService(507): curLp=null
10-18 08:09:16.607 D/ConnectivityService(507): newLp=InterfaceName: rmnet0 LinkAddresses: [10.39.16.55/28,] Routes: [0.0.0.0/0 -> 10.39.16.49,] DnsAddresses: [139.7.30.126,139.7.30.125,]
10-18 08:09:16.607 D/ConnectivityService(507): Adding 10.39.16.49/32 -> 0.0.0.0 for interface rmnet0
10-18 08:09:16.607 D/ConnectivityService(507): Routes in main table - [ [10.39.16.49/32 -> 0.0.0.0] ]
10-18 08:09:16.607 D/StatusBar.NetworkController(654): refreshViews: Data not connected!! Set no data type icon
10-18 08:09:16.607 D/StatusBar.NetworkController(654): refreshViews connected={ } level=3 combinedSignalIconId=0x7f0200a6/com.android.systemui:drawable/stat_sys_signal_3_fully combinedActivityIconId=0x0 mobileLabel=Vodafone.de wifiLabel= emergencyOnly=false combinedLabel=Vodafone.de mAirplaneMode=false mDataActivity=0 mPhoneSignalIconId=0x7f0200a6 mDataDirectionIconId=0x0 mDataSignalIconId=0x7f0200a6 mDataTypeIconId=0x0 mNoSimIconId=0x0 mWifiIconId=0x0 mBluetoothTetherIconId=0x10808c3
10-18 08:09:16.607 D/ConnectivityService(507): Adding 0.0.0.0/0 -> 10.39.16.49 for interface rmnet0
10-18 08:09:16.607 D/ConnectivityService(507): Routes in main table - [ [10.39.16.49/32 -> 0.0.0.0, 0.0.0.0/0 -> 10.39.16.49] ]
10-18 08:09:16.617 D/StatusBar.NetworkController(654): onDataConnectionStateChanged: state=2 type=8
10-18 08:09:16.627 D/StatusBar.NetworkController(654): refreshViews connected={ data } level=3 combinedSignalIconId=0x7f0200a6/com.android.systemui:drawable/stat_sys_signal_3_fully combinedActivityIconId=0x7f0200a9 mobileLabel=Vodafone.de wifiLabel= emergencyOnly=false combinedLabel=Vodafone.de mAirplaneMode=false mDataActivity=0 mPhoneSignalIconId=0x7f0200a6 mDataDirectionIconId=0x7f020087 mDataSignalIconId=0x7f0200a6 mDataTypeIconId=0x7f02007b mNoSimIconId=0x0 mWifiIconId=0x0 mBluetoothTetherIconId=0x10808c3
10-18 08:09:16.627 D/StatusBar.NetworkController(654): changing data overlay icon id to 2130837673
10-18 08:09:16.657 D/StatusBar.NetworkController(654): onDataActivity: direction=0
10-18 08:09:16.657 D/StatusBar.NetworkController(654): refreshViews connected={ data } level=3 combinedSignalIconId=0x7f0200a6/com.android.systemui:drawable/stat_sys_signal_3_fully combinedActivityIconId=0x7f0200a9 mobileLabel=Vodafone.de wifiLabel= emergencyOnly=false combinedLabel=Vodafone.de mAirplaneMode=false mDataActivity=0 mPhoneSignalIconId=0x7f0200a6 mDataDirectionIconId=0x7f020087 mDataSignalIconId=0x7f0200a6 mDataTypeIconId=0x7f02007b mNoSimIconId=0x0 mWifiIconId=0x0 mBluetoothTetherIconId=0x10808c3
10-18 08:09:16.697 D/ConnectivityService(507): Adding 10.39.16.49/32 -> 0.0.0.0 for interface rmnet0
10-18 08:09:16.697 D/ConnectivityService(507): Routes in main table - [ [10.39.16.49/32 -> 0.0.0.0, 0.0.0.0/0 -> 10.39.16.49, 10.39.16.49/32 -> 0.0.0.0] ]
10-18 08:09:16.707 D/ConnectivityService(507): Adding 139.7.30.126/32 -> 10.39.16.49 for interface rmnet0
10-18 08:09:16.707 D/ConnectivityService(507): Routes in main table - [ [10.39.16.49/32 -> 0.0.0.0, 0.0.0.0/0 -> 10.39.16.49, 10.39.16.49/32 -> 0.0.0.0, 139.7.30.126/32 -> 10.39.16.49] ]
10-18 08:09:16.707 D/ConnectivityService(507): Adding 10.39.16.49/32 -> 0.0.0.0 for interface rmnet0
10-18 08:09:16.707 D/ConnectivityService(507): Routes in main table - [ [10.39.16.49/32 -> 0.0.0.0, 0.0.0.0/0 -> 10.39.16.49, 10.39.16.49/32 -> 0.0.0.0, 139.7.30.126/32 -> 10.39.16.49, 10.39.16.49/32 -> 0.0.0.0] ]
10-18 08:09:16.707 D/ConnectivityService(507): Adding 139.7.30.125/32 -> 10.39.16.49 for interface rmnet0
10-18 08:09:16.707 D/ConnectivityService(507): Routes in main table - [ [10.39.16.49/32 -> 0.0.0.0, 0.0.0.0/0 -> 10.39.16.49, 10.39.16.49/32 -> 0.0.0.0, 139.7.30.126/32 -> 10.39.16.49, 10.39.16.49/32 -> 0.0.0.0, 139.7.30.125/32 -> 10.39.16.49] ]
10-18 08:09:16.707 D/ConnectivityService(507): resetting DNS cache for rmnet0
10-18 08:09:16.717 D/ConnectivityService(507): sendStickyBroadcast: action=android.net.conn.CONNECTIVITY_CHANGE_IMMEDIATE
10-18 08:09:16.717 D/ConnectivityService(507): sendStickyBroadcastDelayed: delayMs=3000, action=android.net.conn.CONNECTIVITY_CHANGE
10-18 08:09:17.507 D/ConnectivityService(507): sendStickyBroadcast: action=android.net.conn.CONNECTIVITY_CHANGE
10-18 08:09:17.527 D/StatusBar.NetworkController(654): updateConnectivity: intent=Intent { act=android.net.conn.CONNECTIVITY_CHANGE flg=0x8000010 (has extras) }
10-18 08:09:17.527 D/StatusBar.NetworkController(654): updateConnectivity: networkInfo=NetworkInfo: type: mobile[HSDPA], state: CONNECTED/CONNECTED, reason: dataEnabled, extra: web.vodafone.de, roaming: false, failover: true, isAvailable: true
10-18 08:09:17.527 D/StatusBar.NetworkController(654): updateConnectivity: connectionStatus=0
10-18 08:09:17.547 D/StatusBar.NetworkController(654): refreshViews connected={ data } level=3 combinedSignalIconId=0x7f0200a5/com.android.systemui:drawable/stat_sys_signal_3 combinedActivityIconId=0x7f0200a9 mobileLabel=Vodafone.de wifiLabel= emergencyOnly=false combinedLabel=Vodafone.de mAirplaneMode=false mDataActivity=0 mPhoneSignalIconId=0x7f0200a5 mDataDirectionIconId=0x7f02007b mDataSignalIconId=0x7f0200a5 mDataTypeIconId=0x7f02007b mNoSimIconId=0x0 mWifiIconId=0x0 mBluetoothTetherIconId=0x10808c3
10-18 08:09:17.587 D/ConnectivityService(507): NetTransition Wakelock for WifiStateMachine released by timeout
10-18 08:09:17.607 D/StatusBar.NetworkController(654): onDataActivity: direction=2
10-18 08:09:17.617 D/StatusBar.NetworkController(654): refreshViews connected={ data } level=3 combinedSignalIconId=0x7f0200a5/com.android.systemui:drawable/stat_sys_signal_3 combinedActivityIconId=0x7f0200ae mobileLabel=Vodafone.de wifiLabel= emergencyOnly=false combinedLabel=Vodafone.de mAirplaneMode=false mDataActivity=2 mPhoneSignalIconId=0x7f0200a5 mDataDirectionIconId=0x7f02007b mDataSignalIconId=0x7f0200a5 mDataTypeIconId=0x7f02007b mNoSimIconId=0x0 mWifiIconId=0x0 mBluetoothTetherIconId=0x10808c3
10-18 08:09:17.617 D/StatusBar.NetworkController(654): changing data overlay icon id to 2130837678
10-18 08:09:17.647 D/ConnectivityService(507): sendStickyBroadcast: action=android.net.conn.CONNECTIVITY_CHANGE
10-18 08:09:17.647 I/ActivityManager(507): Start proc com.sonyericsson.idd.agent for broadcast com.sonyericsson.idd.agent/.IDDEnabledBroadcastReceiver: pid=8612 uid=10051 gids={3003, 1015, 1023, 1028}
10-18 08:09:17.677 D/StatusBar.NetworkController(654): updateConnectivity: intent=Intent { act=android.net.conn.CONNECTIVITY_CHANGE flg=0x8000010 (has extras) }
10-18 08:09:17.677 D/StatusBar.NetworkController(654): updateConnectivity: networkInfo=NetworkInfo: type: mobile[HSDPA], state: CONNECTED/CONNECTED, reason: dataEnabled, extra: web.vodafone.de, roaming: false, failover: true, isAvailable: true
10-18 08:09:17.677 D/StatusBar.NetworkController(654): updateConnectivity: connectionStatus=0
10-18 08:09:17.687 D/StatusBar.NetworkController(654): refreshViews connected={ data } level=3 combinedSignalIconId=0x7f0200a5/com.android.systemui:drawable/stat_sys_signal_3 combinedActivityIconId=0x7f0200ae mobileLabel=Vodafone.de wifiLabel= emergencyOnly=false combinedLabel=Vodafone.de mAirplaneMode=false mDataActivity=2 mPhoneSignalIconId=0x7f0200a5 mDataDirectionIconId=0x7f02007b mDataSignalIconId=0x7f0200a5 mDataTypeIconId=0x7f02007b mNoSimIconId=0x0 mWifiIconId=0x0 mBluetoothTetherIconId=0x10808c3
10-18 08:09:17.727 I/ActivityManager(507): Start proc com.google.android.apps.plus for service com.google.android.apps.plus/.service.EsSyncAdapterService: pid=8632 uid=10083 gids={3003, 3002, 1015, 1023, 1006, 1028}
10-18 08:09:17.777 I/ActivityManager(507): Start proc com.google.android.apps.uploader for broadcast com.google.android.apps.uploader/com.google.android.picasasync.ConnectivityReceiver: pid=8645 uid=10061 gids={3003, 1015, 1023, 1028}
10-18 08:09:17.807 I/ActivityManager(507): No longer want com.metago.astro (pid 8152): hidden #16
10-18 08:09:17.957 I/ActivityManager(507): No longer want com.android.email (pid 5900): hidden #16
10-18 08:09:18.517 I/ActivityManager(507): Start proc com.google.android.gms for broadcast com.google.android.gms/.gcm.GmsAutoStarter: pid=8673 uid=10023 gids={3003, 1015, 1023, 1028, 2001, 1007, 3006, 1006}
10-18 08:09:18.767 I/ActivityManager(507): No longer want com.sonymobile.socialengine.plugins (pid 8244): hidden #16
10-18 08:09:18.817 I/ActivityManager(507): Start proc com.google.android.youtube for broadcast com.google.android.youtube/.app.prefetch.PrefetchService$DeviceStateReceiver: pid=8701 uid=10154 gids={3003, 1015, 1023, 1006, 1028}