Re: PREEMPT_RT (2.6.33-rt17) disabled printk-to-console after console_init

From: Sujit K M
Date: Thu May 20 2010 - 05:32:18 EST


Sorry does not help as it is very old and does not seem to provide
information regarding
Real Time Linux. But the section for

setserial -g /dev/ttyS[01]

and

/etc/inittab modifications are pointer to the changes required for
Real Timliness.

The problem is that baud rate of the COM/TTY port may require some modification.
I Think you will need to have an Critical Section for the Driver to
timeout in sync with
the baud rate.

Hope what I have said makes sense.


On Thu, May 20, 2010 at 2:55 PM, Sujit K M <sjt.kar@xxxxxxxxx> wrote:
> http://www.vanemery.com/Linux/Serial/serial-console.html
>
> Could this be of help.
>
> On Thu, May 20, 2010 at 2:03 PM, Nikita V. Youshchenko <yoush@xxxxxxxxx> wrote:
>>> > I could not get dmesg output to console/serial and
>>> > klogd(/var/log/messages) anymore with 2.6.33-rt17 _after_ the kernel
>>> > boot is done(on non-RT kernel it works fine). I made below changes it
>>> > starts to work again, however I'm unsure how safe the change is.
>>> > Please advise.
>>>
>>> Well, obviously it's unsafe if you remove safety checks. And if you
>>> care to look at the changelog of kernel/printk.c you'll find out why.
>>
>> Hmm... did a quick look and could not find anything related there.
>> Could you please give a pointer?
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>
>
>
> --
> -- Sujit K M
>
> blog(http://kmsujit.blogspot.com/)
>



--
-- Sujit K M

blog(http://kmsujit.blogspot.com/)
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