Uart0 interrupts on high level on APU.1D4 –ver. 2.2



  • Sometimes, after two or more days, without serial connection established on a full installation from USB stick to mSATA 16GB, the interrupts on uart0 (console) are on high level:

    [2.2-RELEASE][admin@box.lan]/root: vmstat -i
    interrupt                          total       rate
    irq4: uart0                    526788821       1896
    irq16: ath1                     38711555        139
    irq17: ehci0 ehci1+               185438          0
    irq18: ohci0 ohci1*                    2          0
    irq19: ath0 ahci0               11836455         42
    irq256: hpet0:t0               309913938       1115
    irq257: hpet0:t1               110004189        395
    irq259: re0                     61685974        222
    irq260: re1                        85377          0
    irq261: re2                     32864397        118
    Total                         1092076146       3930
    
    [2.2-RELEASE][admin@box.lan]/root: top -aSH
    ...
      PID USERNAME   PRI NICE   SIZE    RES STATE   C   TIME    WCPU COMMAND
       11 root       155 ki31     0K    32K RUN     1  46.8H  89.60% [idle{idle: cpu1}]
       11 root       155 ki31     0K    32K CPU0    0  46.2H  87.50% [idle{idle: cpu0}]
       12 root       -76    -     0K   288K WAIT    0   1:36   3.37% [intr{swi0: uart uart}]
    ...
    
    

    Connecting to the serial console shows nothing, hitting ENTER -> nothing
    Strg+C brings up a shell with prompt

    #
    # exit
    
    FreeBSD/amd64 (box.lan) (ttyu0)
    
    *** Welcome to pfSense 2.2-RELEASE-pfSense (amd64) on svea ***
    ...
    
    

    and solved the problem! The interrupts are gone!

    Any ideas?


  • Rebel Alliance Developer Netgate

    Any messages in the main system log?

    Was this a fresh 2.2 install or an upgraded 2.1.5?



  • Was a fresh 2.2 RC install with some upgrade steps finally to Release.
    Doesn't checked the system log, sorry…



  • No messages in main system log regarding these issue.

    It returns for 6-12 h every 6-12 h currently.

    Any help?



  • Ok, the problem was the connected serial cable with the other end open for all the time, means without termination of a serial device or serial-usb adapter. May be some signal reflection/induction on the open end back to the serial port on the APU.1D4 board.