>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).

Well, I can repeat it as often as you like. The serial hang occurrs
unpredictibly and all too often for me, using an old DataGeneral VT200.
Strangely enough, PPP through the modem port is unaffected and only
ever drops due to phoneline problems

>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.

Yeah, occasionally I have to hit CR twice to get a password prompt.
However, the hangs are worse - I'm yet to try dropping to single user
and back up - thanks for the idea (sorry, I don't have a name, deleted
mail).

>Sounds like either we're dropping an interrupt, or there's a bug
>in our handling of block-finished events.

I'm about a week or less away from compiling my own kernels, so I might
have a chance to look into it then. Is there a way of looking at serial
level port stats from userland?

>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).

Nope, no pattern. And different flow control protocols don't seem to help
either.

>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.

True, sounds like time well spent.

Cheers,
--
Paul Ripke
BHP Information Technology
Ope VMS, AXP & UNIX (AIX, HP/UX, DG/UX, SCO, SGI, Digital, SunOS...) Sysadmin
Computer Centre,    Five Islands Rd,    Port Kembla,    NSW 2505,   AUSTRALIA
  ripke.paul.pr@bhp.com.au     weripp@itwol.bhp.com.au     pjr02@uow.edu.au
            Anyone wishing to lay claim to the opinions expressed
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