Re: 2.1.8 problems

Theodore Y. Ts'o (
Wed, 13 Nov 1996 00:04:05 -0500

From: Michael Nelson <>
Date: Sun, 10 Nov 1996 17:45:40 -0800 (PST)

Bernhard Rosenkraenzer <> wrote:
> Hello,
> I've just compiled & installed 2.1.8. Everything seems to work fine,
> except for 2 problems:
> (1) There's a problem with serial ports or CSLIP - With 2.1.8, I can
> connect to my ISP (i.e. get a carrier), but only about half the
> characters are getting through.

I reported the same on ppp to Linus a couple days ago. He sent me a
patch to try within hours, but it didn't fix the "dropped characters on
serial port" problem.

I'm running 2.0.25 now until the 2.1.x serial port problems are fixed.

Could people who are reporting "serial problems" with Linux report such
problems to linux-kernel with much greater detail? i.e., what version
were you using before (where things were working), and what was the
first kernel version that you upgraded to that started failing.

What UART do you have in your system? What UART was detected in the
bootup messages? What application were you using, and how did you
determine that "half the characters are getting through"? What does
that mean, anyway? Is that using a telnet session, and only have the
characters you are typing aren't going through? Do you mean 50% of your
ping packets are going through? Or something else?

I've tried using PPP with the 2.1.8 kernel, ppp 2.2.0f, a 16550A UART,
and a USR Robotics modem, and it works just fine. So I can't duplicate
your bug report, which makes it very hard to figure out what actually
needs fixing.

- Ted