Re: [9fans] loosing characters in serial connection to bitsy

Re: [9fans] loosing characters in serial connection to bitsy

[presotto]

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Perhaps we're not setting up the fifo's correctly flor the uart
on the fifo?  What flavor/speed laptop is it?

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From: Axel Belinfante <Axel.Belinfante@cs.utwente.nl>
To: 9fans@cse.psu.edu
Subject: [9fans] loosing characters in serial connection to bitsy
Date: Tue, 29 Oct 2002 11:10:39 +0100
Message-ID: <200210291010.g9TAAd126420@zamenhof.cs.utwente.nl>

When I connect the bitsy serial line to my desktop, con works as expected.
When I connect it to a laptop (with only one serial connector)
I loose characters of the boot loader output, sometimes I see its complete
prompt (boot>) somtimes only half of it, and the same for other output.

Any ideas where to start looking, what could be wrong?
I _think_ that in the past consolefs worked OK on the same laptop
(but maybe I changed kernels in the mean time).

Thanks,
Axel.

Re: [9fans] loosing characters in serial connection to bitsy

[Axel Belinfante]

> Perhaps we're not setting up the fifo's correctly for the uart
> on the fifo?  What flavor/speed laptop is it?

Toshiba tecra 8000 (about 3 years old).
speed = processor speed? pentium III/450 Mhz

Re: [9fans] loosing characters in serial connection to bitsy

[andrey mirtchovski]

well.. serial lines sometimes just drop characters... i would suspect that
by setting the speed to 115200 the loss will increase.

someone i know used to laugh at me for this -- 'p9 is so slow it can't
even cope with a fast serial line' -- until it was confirmed that
linux would drop serial line input much the same way, though not as much.


andrey

On Tue, 29 Oct 2002, Axel Belinfante wrote:

> > Perhaps we're not setting up the fifo's correctly for the uart
> > on the fifo?  What flavor/speed laptop is it?
>
> Toshiba tecra 8000 (about 3 years old).
> speed = processor speed? pentium III/450 Mhz
>

Re: [9fans] loosing characters in serial connection to bitsy

[jmk]

As far as I remember, we don't enable FIFOs by default, you have to
do that explicitly via a ctl message. That sometimes helps.

[9fans] loosing characters in serial connection to bitsy

[Axel Belinfante]

When I connect the bitsy serial line to my desktop, con works as expected.
When I connect it to a laptop (with only one serial connector)
I loose characters of the boot loader output, sometimes I see its complete
prompt (boot>) somtimes only half of it, and the same for other output.

Any ideas where to start looking, what could be wrong?
I _think_ that in the past consolefs worked OK on the same laptop
(but maybe I changed kernels in the mean time).

Thanks,
Axel.