Re: ia64 stability problems on HP rx2600-2

[Bjorn Helgaas <bjorn.helgaas@hp.com>]

On Tue, 2005-03-29 at 15:11 -0800, David Mosberger wrote:
>   Michael> In EFI I can select mainly 3 devices (I think its first
>   Michael> Serial, MP serial and VGA, and the serials have ANSI, vt100
>   Michael> etc to chose). When I select first serial or vga, kernel
>   Michael> boots without output but fine. I add console=ttyS3 and I
>   Michael> can see everything over MP again.  But if I choose the
>   Michael> second output device, I can see the kerenl boot without the
>   Michael> need of a console= line. But it says:
> 
>   Michael> NET: Regi
> 
>   Michael> and then everything hangs. I even have to reset the MP to
>   Michael> get access to the console again. Any hint?
> 
> Well, I really don't have any experience with this (I don't normally
> use MP console) but I wonder whether something is seeing a Ctrl-S and
> stopping console output (the next character that would normally be
> printed is an "s").  Is this at 9600 baud?
> 
> Bjorn, do you have any idea?

I was going to suggest some sort of flow control problem, too.
Internally, we typically use the built-in port (just developer
preference), but we do exercise the MP occasionally, and we
haven't seen the problem you describe.

I assume you're connected to the MP via serial (as opposed to
LAN).  Our MP serial port is usually connected to Cyclades
terminal servers, with the following MP serial config (use
"CA" at the MP prompt):

  Local Console Serial Port bit rate: 115200 bits/s 
  Local Console Serial Port Flow Control: Hardware 
  Local Console Serial Port Terminal Type: VT100+
  Remote Console Serial Port Modem Protocol: CCITT
  Remote Console Serial Port Modem bit rate: 38400 bits/s 
  Remote Console Serial Port Modem Flow Control: Hardware 
  Remote Console Serial Port Modem Transmit Configuration Strings: Enabled 
  Remote Console Serial Port Modem Presence: always connected

The Cyclades are configured with no flow control.