Re: silo overflows -- what can I do about this?

[Matthew Dillon <dillon@xxxxxxxxxxxxxxxxxxxx>]

:Okay, so I was working via the console port (i.e. DFly box connected to 
:  Firewall via serial port) of my PIX firewall and I kept getting these 
:errors. These errors made it quite impossible to configure the firewall 
:because I was unable to recieve the output from the PIX device.
:
:Error Messages (/var/log/messages):
:Oct 17 17:40:04 dfly kernel: sio1: 2 more silo overflows (total 23)
:Oct 17 17:40:06 dfly kernel: sio1: 4 more silo overflows (total 27)
:Oct 17 17:41:22 dfly kernel: sio1: 7 more silo overflows (total 34)
:Oct 17 17:41:24 dfly kernel: sio1: 9 more silo overflows (total 43)
:Oct 17 17:41:25 dfly kernel: sio1: 4 more silo overflows (total 47)
:Oct 17 17:41:38 dfly kernel: sio1: 2 more silo overflows (total 49)
:Oct 17 17:49:36 dfly kernel: sio1: 1 more silo overflow (total 50)
:Oct 17 17:49:53 dfly kernel: sio1: 1 more silo overflow (total 51)
:Oct 17 17:49:57 dfly kernel: sio1: 1 more silo overflow (total 52)
:Oct 17 17:50:02 dfly kernel: sio1: 1 more silo overflow (total 53)
:
:Is there anything I can do about these errors? The man page for sio says 
:that it's an interupt problem. Any help would be appreciated.
:
:Thanks!
:
:Joey

    It may be possible to reduce the instances of the problem
    by using a different fifo trigger point, but there is always
    going to be an issue of some sort, especially if the IRQ
    used by the serial port is shared with another device. 

    Try changing FIFO_RX_MEDH to FIFO_RX_LOW around line 2281
    of /usr/src/sys/dev/serial/sio/sio.c.

    Also post your 'dmesg' output.

					-Matt
					Matthew Dillon 
					<dillon@xxxxxxxxxxxxx>