Subject: Re: Serial console hangs
To: Daniel Eggert <danieleggert@mac.com>
From: Henry B. Hotz <hotz@jpl.nasa.gov>
List: port-macppc
Date: 03/14/2003 17:52:31
At 10:53 AM +0100 3/14/03, Daniel Eggert wrote:
>On torsdag, mar 13, 2003, at 10:49 Europe/Copenhagen, Daniel Eggert wrote:
>
>>
>>On torsdag, mar 13, 2003, at 02:16 Europe/Copenhagen, John Gordon wrote:
>>>The problem is that sometimes when a lot of data is passing across 
>>>the serial
>>>link (e.g. scrolling down a page in an editor) the link will hang. 
>>>The system
>>>seems to be still alive (I can ping it). I will set up ssh support 
>>>on it next
>>>so I can take a look at what is happening, but thought I'd ask if 
>>>anybody has
>>>seen anything like this before?
>>>
>>
>>This is a know problem. Try using ssh instead if you can. Hopefully 
>>some day someone will fix this. It's a bug in the driver for the 
>>serial port.
>>
>
>It is in the PR-database as #10540.
>
>Is anybody working on a fix? Does anyone have a clue, what could be 
>wrong? ..or how to investigate this? I guess the bug is somewhere 
>inside src/sys/arch/macppc/dev/zs.c and I wouldn't mind helping...
>
>Any comments?

I think the last person to look at this seriously and comment on it 
was John Klos.  He came to the conclusion that there was something 
whacked in the MI infrastructure w.r.t. how interrupts were traded 
among parts of the system.

The zs driver is shared with the mac68k and sun ports, and was pretty 
good in general once.  There could be hardware issues with the macppc 
hardware implementation of course.

AFAIK no one is actively working on it, but there are a lot of us who 
think it would real nice if it worked (like it used to on mac68k). 
Personally my interest decreased a lot after I finally broke down and 
got a DSL line though.
-- 
The opinions expressed in this message are mine,
not those of Caltech, JPL, NASA, or the US Government.
Henry.B.Hotz@jpl.nasa.gov, or hbhotz@oxy.edu