I don't know the specific settings the original poster is using (I just
caught this thread recently) but I had a similar lockup type behavior about
2 months ago with a Feb 12 (or their abouts) kernel.  At the time I was
running ppp at 57.6kbaud from a Mac IIx to a PowerMac, and occasionaly it
would lock up on me, usually during a large transfer of data.  I think I
had hardware flow control enabled (though I seem to recall someone saying
it was broken back then?)

At any rate, I dropped down to 38.4kb and the lockups disappeared.  Of
course that was also about the time that I got a newer kernel working (Late
Feb, I forget the exact date), so I don't know which fixed the problem!

In March, I had both serial ports working at 38.4kb pretty heavily and
never had a problem.

Hope this helps!

>Grr. I've been following this thread with displeasure since it started.
>It sounds like a nasty intermittent problem. :-( Hopefully someone can
>reproduce the problem (or get hit with it often-enough to make
>diagnostics possable).
>
>The original problem I heard about was that sometimes on a serial
>terminal the output just seems to stop for a while, and then all of a
>sudden it will start up with a flood of characters. Nothing else on the
>machine seems stalled at this point.
>
>Sounds like either we're dropping an interrupt, or there's a bug
>in our handling of block-finished events.
>
>Has anyone found rhyme or reason to when characters start back up?
>Also, was any form of flow control on at the time (I gather not, but
>want to make sure).
>
>Unfortunately we're within a month of having a new serial driver, and
>I've been staring at it for the last few months instead of ser.c. I
>doubt it will fix the error, but I'd rather debug it than debug the
>soon-to-go-away ser.c driver.
>
>> > In other words, is NetBSD crashing or is the serial interface getting
>> > blocked somehow (or not being serviced properly or being intentionally
>> > paused)?
>> Oh, its definitely an issue with the serial driver.  The whole time, you can
>> telnet into the machine and do anything you want as normal.  When its forzen,
>> the believes there is still me logged into the serial prot (it won't let me
>> kill the shell in fact) .... it is as if the characters are being suddenly
>> buffered up or put somewhere.  The system at a topical level seems to be
>> convinced it is still connected.
>
>Technically it's the serial driver+tty system. Transmitted data is always
>buffered; normally, though, the data flows out the buffers fairly
>quickly.
>
>take care,
>
>Bill


--
Aaron Scott Magill                                             amagill@uiuc.edu
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