Preventing MM from probing specific serial ports on supported modems

Tue Apr 26 12:39:21 UTC 2016

I'm sure there must be some way to do this, but I'm unable to figure out
how.  I want MM to completely ignore the GPS NMEA port on the MC7455.  I
want that port to be handled by gpsd.  And having two daemons touching
the same port does feel a bit yucky.  Besides, MM doesn't really deal
all that well with NMEA and sometimes crashes while running the AT
probe:

ModemManager[23206]: <debug> [1461673282.655968] [mm-port-serial-at.c:459] debug_log(): (ttyUSB1): --> 'AT<CR>'
ModemManager[23206]: <debug> [1461673282.656840] [mm-port-serial-at.c:459] debug_log(): (ttyUSB2): --> 'AT<CR>'
ModemManager[23206]: <debug> [1461673282.657650] [mm-port-serial-at.c:459] debug_log(): (ttyUSB0): --> 'AT<CR>'
ModemManager[23206]: <debug> [1461673282.857504] [mm-port-serial-at.c:459] debug_log(): (ttyUSB1): <-- '$GPGSV,3,1,09,01,18,016,,06,,,,10,19,285,,11,05,007,*4F<CR><LF>\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0$GPGSV,3,2,09,12,34,224,,13,,,,14,17,317,,15,22,191,*48<CR><LF>\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0$GPGSV,3,3,09,17,45,077,*47<CR><LF>\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0$GPVTG,,T,,M,,N,,K,N*2C<CR><LF>\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0$GPGSA,A,1,,,,,,,,,,,,,,,*1E<CR><LF>\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0$GPGGA,,,,,,0,,,,,,,,*66<CR><LF>\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0$GPRMC,,V,,,,,,,,,,N*53<CR><LF>\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0'
ModemManager[23206]: <debug> [1461673282.858055] [mm-serial-parsers.c:191] mm_serial_parser_v1_parse(): Got response filtered in serial port: Not an AT response
ModemManager[23206]: <debug> [1461673282.858341] [mm-port-probe-at.c:43] mm_port_probe_response_processor_is_at(): Parsing AT got: 'Not an AT response'
ModemManager[23206]: <debug> [1461673282.858593] [mm-plugin-manager.c:519] port_context_next(): [plugin manager] task 3,ttyUSB1: checking with plugin 'Generic'
ModemManager[23206]: <debug> [1461673282.858850] [mm-plugin.c:804] mm_plugin_supports_port(): (Generic) [ttyUSB1] probe required: 'at, qcdm'
**
ERROR:mm-port-probe.c:1316:mm_port_probe_run: assertion failed: (self->priv->task == NULL)
Aborted

So I tried setting ID_MM_PORT_IGNORE in the udev rule I use to assign
the port to gpsd:

 SUBSYSTEM=="tty",ACTION=="add",ENV{ID_VENDOR_ID}=="1199",ATTRS{bInterfaceNumber}=="02",SYMLINK="gps%n",ENV{ID_MM_PORT_IGNORE}="1",RUN+="/usr/sbin/gpsdctl add $devnode"

This does seem to work in the way that MM logs the port as 'ignored',
but only after going through full AT port probing:

Apr 26 13:56:34 nemi ModemManager[5861]: <debug> [1461671794.710192] [mm-plugin-manager.c:599] port_context_run(): [plugin manager] task 7,ttyUSB1: found '2' plugins to try
Apr 26 13:56:34 nemi ModemManager[5861]: <debug> [1461671794.710429] [mm-plugin-manager.c:622] port_context_run(): [plugin manager] task 7,ttyUSB1: will try with plugin 'Sierra'
Apr 26 13:56:34 nemi ModemManager[5861]: <debug> [1461671794.710655] [mm-plugin-manager.c:622] port_context_run(): [plugin manager] task 7,ttyUSB1: will try with plugin 'Generic'
Apr 26 13:56:34 nemi ModemManager[5861]: <debug> [1461671794.710903] [mm-plugin-manager.c:635] port_context_run(): [plugin manager) task 7,ttyUSB1: started
Apr 26 13:56:34 nemi ModemManager[5861]: <debug> [1461671794.711129] [mm-plugin-manager.c:519] port_context_next(): [plugin manager] task 7,ttyUSB1: checking with plugin 'Sierra'
Apr 26 13:56:34 nemi ModemManager[5861]: <debug> [1461671794.711274] [mm-plugin.c:804] mm_plugin_supports_port(): (Sierra) [ttyUSB1] probe required: 'at, qcdm'
Apr 26 13:56:34 nemi ModemManager[5861]: <debug> [1461671794.711414] [mm-port-probe.c:1356] mm_port_probe_run(): (tty/ttyUSB1) launching port probing: 'at, qcdm'
Apr 26 13:56:34 nemi ModemManager[5861]: <debug> [1461671794.764073] [mm-port-serial.c:1159] mm_port_serial_open(): (ttyUSB1) opening serial port...
Apr 26 13:56:34 nemi ModemManager[5861]: <warn>  [1461671794.764573] [mm-port-serial.c:514] real_config_fd(): (ttyUSB1): port attributes not fully set
Apr 26 13:56:34 nemi ModemManager[5861]: <debug> [1461671794.764750] [mm-port-serial.c:1297] mm_port_serial_open(): (ttyUSB1) device open count is 1 (open)
Apr 26 13:56:34 nemi ModemManager[5861]: <debug> [1461671794.771887]
[mm-port-serial-at.c:459] debug_log(): (ttyUSB1): <--
'$GPGSV,2,1,08,01,19,028,,10,24,295,,11,11,014,,12,22,223,*7D<CR><LF>\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0$GPGSV,2,2,08,13,11,163,,14,08,320,,15,33,195,,17,43,094,*7E<CR><LF>\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0$GPVTG,,T,,M,,N,,K,N*2C<CR><LF>\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0$GPGSA,A,1,,,,,,,,,,,,,,,*1E<CR><LF>\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0$GPGGA,,,,,,0,,,,,,,,*66<CR><LF>\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0$GPRMC,,V,,,,,,,,,,N*53<CR><LF>\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0$GPGSV,2,1,08,01,19,028,,10,24,295,,11,11,014,,12,22,223,*7D<CR><LF>\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0$GPGSV,2,2,08,13,11,163,,14,08,320,,15,33,195,,17,43,094,*7E<CR><LF>\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0$GPVTG,,T,,M,,N,,K,N*2C<CR><LF>\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0$GPGSA,A,1,,,,,,,,,,,,,,,*1E<CR><LF>\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\
0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0$GPGGA,,,,,,0,,,,,,,,*66<CR><LF>\0\0\0\0\0\0\0\0\0\0\0\0'
Apr 26 13:56:34 nemi ModemManager[5861]: <debug> [1461671794.774673] [mm-port-serial-at.c:459] debug_log(): (ttyUSB1): <-- '\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0$GPRMC,,V,,,,,,,,,,N*53<CR><LF>\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0'
Apr 26 13:56:34 nemi ModemManager[5861]: <debug> [1461671794.866337] [mm-port-serial-at.c:459] debug_log(): (ttyUSB1): --> 'AT<CR>'
Apr 26 13:56:35 nemi ModemManager[5861]: <debug> [1461671795.072836] [mm-plugin-manager.c:366] port_context_set_suggestion(): [plugin manager] task 7,ttyUSB1: got suggested plugin (Sierra)
Apr 26 13:56:35 nemi ModemManager[5861]: <debug> [1461671795.073377] [mm-plugin-manager.c:1005] device_context_continue(): [plugin Manager] task 7: still 6 running probes (6 active): ttyUSB1, wwan0, wwan1, cdc-wdm1, cdc-wdm0, ttyUSB0
Apr 26 13:56:35 nemi ModemManager[5861]: <debug> [1461671795.093339] [mm-plugin-manager.c:1005] device_context_continue(): [plugin Manager] task 7: still 5 running probes (5 active): ttyUSB1, wwan1, cdc-wdm1, cdc-wdm0, ttyUSB0
Apr 26 13:56:35 nemi ModemManager[5861]: <debug> [1461671795.094515] [mm-plugin-manager.c:1005] device_context_continue(): [plugin Manager] task 7: still 4 running probes (4 active): ttyUSB1, cdc-wdm1, cdc-wdm0, ttyUSB0
Apr 26 13:56:35 nemi ModemManager[5861]: <debug> [1461671795.665222] [mm-port-serial-at.c:459] debug_log(): (ttyUSB1): <-- '$GPGSV,2,1,08,01,19,028,,10,24,295,,11,11,014,,12,22,223,*7D<CR><LF>\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0'
Apr 26 13:56:35 nemi ModemManager[5861]: <debug> [1461671795.665560] [mm-plugin-manager.c:390] port_context_unsupported(): [plugin manager] task 7,ttyUSB1: ignoring port unsupported by physical modem's plugin
Apr 26 13:56:35 nemi ModemManager[5861]: <debug> [1461671795.665620] [mm-plugin-manager.c:265] port_context_complete(): [plugin manager] task 7,ttyUSB1: finished in '2.311693' seconds
Apr 26 13:56:35 nemi ModemManager[5861]: <debug> [1461671795.665687] [mm-plugin-manager.c:886] device_context_set_best_plugin(): [plugin manager] task 7,ttyUSB1: assuming port can be handled by the 'Sierra' plugin
Apr 26 13:56:35 nemi ModemManager[5861]: <debug> [1461671795.665833] [mm-port-serial.c:1354] _close_internal(): (ttyUSB1) device open count is 0 (close)
Apr 26 13:56:35 nemi ModemManager[5861]: <debug> [1461671795.665891] [mm-port-serial.c:1370] _close_internal(): (ttyUSB1) closing serial port...
Apr 26 13:56:35 nemi ModemManager[5861]: <debug> [1461671795.679799] [mm-port-serial.c:1419] _close_internal(): (ttyUSB1) serial port closed
Apr 26 13:56:35 nemi ModemManager[5861]: <debug> [1461671795.679951] [mm-port-serial.c:1481] port_serial_close_force(): (ttyUSB1) forced to close port
Apr 26 13:56:44 nemi ModemManager[5861]: <debug> [1461671804.650099] [mm-plugin.c:905] mm_plugin_create_modem(): (tty/ttyUSB1): port is blacklisted
Apr 26 13:56:44 nemi ModemManager[5861]: <debug> [1461671804.650726] [mm-base-modem.c:312] mm_base_modem_grab_port(): (ttyUSB1) type 'ignored' claimed by /sys/devices/pci0000:00/0000:00:1d.7/usb5/5-4

This seems suboptimal at best. It would be nice to avoid the unnecessary
probing, writing AT to a port which is handled by gpsd and reading lots
of NMEA noise back, and of course the occasional crash.

Any advise here?

Bjørn