Subject: Re: Serial port
To: Alexander Hayward <alexander.hayward@lady-margaret-hall.oxford.ac.uk>
From: Mike Pumford <mpumford@black-star.demon.co.uk>
List: port-arm32
Date: 12/19/1996 13:36:05
On Wed, 18 Dec 1996, Alexander Hayward wrote:

> I've been having a few problems with the serial port and recent kernels.
> 
> Sometimes RiscBSD just hangs when dip starts, but not always. I think it 
> may be related to whether I turn the modem on before I boot RiscBSD or 
> not... I'm not sure. Atl-Delete then ctrl-D succeeds in partly rebooting 
> the machine - its sorta clicks and the floppy drive whirrs a bit but it 
> seems to get stuck there. It needs a proper reset before it will restart. 
> I can't remember if this happens all the time either...

Could it be that there is some unread data in the serial chip buffers?
There are a couple of outstanging PR's against the NetBSD/i386 com
driver rlating to this problem. A search of the NetBSD bugs database for
'com' should turn these up. As a plus point modifying the patch given on
the bug report does make the problem go away. There is also another PR
relating to the fact that unless a speed of something other than 9600bps
is used the chip is not initialised properly. RiscBSD seems to have this
problem too.

> 
> The most recent kerne(4871?) seems to give the error 'Com port 
> initialization failed' or something along those lines, before similarly 
> hanging.
Yes I have exactly the same problem when invoking pppd for the second
time.


HTH

Mike