[ntp:hackers] Serial port jitter in FreeBSD
phk at phk.freebsd.dk
Thu Oct 27 03:32:34 PDT 2005
In message <20051026165438.BBF8CBDD1 at ip-64-139-1-69.sjc.megapath.net>, Hal Murr
>> The serial port jitter with refclocks and FreeBSD rackety and mort is
>> rather huge. I have a vague recollection of what can be done about
>> that, specifically to diable the UART FIFO and software queue in the
>> driver. I've done that for most of the systems here, but haven't a
>> clue how to do that with FreeBSD and various motherboards. I've
>> surfed www.freebsd.org with no joy. Help?
>Seems like a good topic for the Wiki.
# man 4 sio
Meaning of flags:
0x00001 shared IRQs
0x00002 disable FIFO
Poul-Henning Kamp | UNIX since Zilog Zeus 3.20
phk at FreeBSD.ORG | TCP/IP since RFC 956
FreeBSD committer | BSD since 4.3-tahoe
Never attribute to malice what can adequately be explained by incompetence.
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