Subject: Re: CG6 and serial port support questions
To: Rick Kelly <rmk@rmkhome.rmkhome.com>
From: David Gilbert <dgilbert@jaywon.pci.on.ca>
List: port-sparc
Date: 03/05/1996 20:56:44
>>>>> "Rick" == Rick Kelly <rmk@rmkhome.rmkhome.com> writes:
Rick> David Gilbert said:
>> The problem is that the chips have a 3 byte FIFO. Those three
>> bytes are easily exhausted. Moreover, when I'm full bore receiving
>> with ppp, the system is hit hard --- close to unusable.
>>
>> While I can't 'know' yet --- I don't have a Sun3 to play with yet,
>> I suspect that 19200 is good fishing for a Sun3.
Rick> When Sun switched from 68k to sparc, the decided that ring
Rick> buffers were a good thing as compared to clists. Thus, a Sun
Rick> 3/60 had better serial throughput than a sparc 1+.
Rick> To this day, the serial driver in Solaris sucks.
Does this mean that it's all a software issue? I know that
the NetBSD uses ring buffers. Would it be possible to rewrite it in
terms of a faster or more efficient structure?
Serial data at 19200 looks like about 2 characters per
microsecond (at 10 bits per character, that's 1920 characters per
second) as a maximum rate. Is it really too much to expect a one
milisecod reaction time to that interupt.
While I'd like to finish support for the multi-port serial
card that I have for my 4/260, I'd also like to see the stock serial
ports working better.
It seems from this discussion, that when I get my 3/260 (in a
little while), it will make a better uucp host that my 4/260, as it
currently stands.
Dave.
--
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|David Gilbert, PCI, Richmond Hill, Ontario. | Two things can only be |
|Mail: dgilbert@jaywon.pci.on.ca | equal if and only if they |
|http://www.pci.on.ca/~dgilbert | are precisely opposite. |
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