If I want to export a track in e.g. Ardour, jack goes into freewheel mode where the device switches off and then comes back "online" after the export finished.
Short pre-story: When stopping jack, the device's control light normally goes from green to off. After about 10 seconds after that you can hear it's internal relay switch. In these 10 secs, the device may not be switched back on (jack fails to start up). When in freewheel mode, if the export is finished within this period of time (before the device "completely" switched off), the device will come back up (green light back on) and all is well. However, if the time limit is exceeded (relay click) then the device will not get back up running. If you now don't kill jack and try to do s.th. else Ardour (and sometimes the whole desktop) will freeze.
I have attached 2 logfiles with one where the device comes back up after the export (ardour_export_success.log) and in the other it fails because the export is too long (ardour_export_fail.log). I have spotted some lines that correspond to the device completely shutting down (shortly before relay clicks, after ~10secs). They are lines
1342700844373598: Warning (ieee1394service.cpp)[ 556] readCycleTimerReg: raw1394_read_cycle_timer: Unknown error -1
1342700844373614: Error (CycleTimerHelper.cpp)[ 779] readCycleTimerWithRetry: Could not read cycle timer register
1342700844373618: Error (CycleTimerHelper.cpp)[ 375] Execute: Could not read cycle timer register
These errors do always occur also when the device is normally switched off.
After the export when the device should get back up but the device already has completely shut down, the errors in lines 4236-4241 happen:
1342700862331612: Error (ieee1394service.cpp) allocateIsoChannelCMP: Could not do CMP from FFC0:-1 to FFC1:-1
1342700862331669: Error (avc_avdevice.cpp)[ 816] startStreamByIndex: Could not allocate ISO channel for SP 0
1342700862331688: Warning (devicemanager.cpp)[ 867] startStreamingOnDevice: Could not start stream 0 of device 0x16a5420
1342700862331706: Warning (devicemanager.cpp)[ 904] startStreaming: Could not start streaming on device 0x16a5420!
1342700862331726: Fatal (ffado.cpp)[ 220] ffado_streaming_start: Could not start the streaming system
firewire ERR: Could not start streaming threads
Cannot start driver
So i thought the problem might be somehow related to the way of the device shutting down?
Note: I have tested a Presonus Firepod and different other Alsa devices which all don't experience these problems. I also had the device running on different firewire controllers (VIA, TI, nvidia, ...) but the error is always there. The error also has been around for as long as i have been using the device with ffado now (2-3 years).