NetBSD rules - Go to the first, previous, next, last, above section, table of contents.

5.13 What are these 'silo overflows' when using the modem?

If you run high baud-rates on your modem, the computer might be to slow to handle all those interrupts from the serial interface and drop some characters, which it calls a 'silo overflow'. To prevent this, try one of the following two solutions:

  1. Try setting bigger buffers for serial i/o. Put the following in your kernel config file an recompile:
    options	"SERIBUF_SIZE=4096"
    options	"SEROBUF_SIZE=32"
    
  2. If this doesn't work, you can try to play with the interrupt system, lowering the clock-interrupts from level 6 to level 4, which will no longer block the serial receive interrupts at level 5. To do so, uncomment the following line from your kernel config file and recompile:
    options	LEV6_DEFER	# defers l6 to l4 (below serial l5)
    

NetBSD rules - Go to the first, previous, next, last, above section, table of contents.