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From: Paul Gortmaker <paul.gortmaker@windriver.com>
To: John Donnelly <john.d@servergy.com>
Cc: linuxppc-dev@lists.ozlabs.org
Subject: Re: Anyone using SysRQ key sequences on console serial port ?
Date: Sun, 16 Feb 2014 10:56:24 -0500	[thread overview]
Message-ID: <CAP=VYLpgMYaSVjTwJ2Q15XB+nozz=OhAPU85Nb9xG_FdP5dcyA@mail.gmail.com> (raw)
In-Reply-To: <CAGtOQbTRSk32p7U=v9V9GPb_ro+WYbKLLCCfrmdypePcHA++mw@mail.gmail.com>

On Fri, Feb 14, 2014 at 3:42 PM, John Donnelly <john.d@servergy.com> wrote:
> Hi,
>
>  I tried using the SysRq hotkey sequence on a serial console -
> 3.11.0-5-powerpc-e500mc system, by issuing a " break " and the system
> immediately wedges after displaying "SysRQ : HELP : " using both "Putty" and
> "Teraterm"  terminal emulators. I know the system is dead because my ssh
> sessions stopped too.

Yes it does work -- or at least it _did_ work.  Make sure your dts has an entry

                        compatible = "fsl,ns16550", "ns16550";

since that enables a workaround I'd added for a hardware errata relating
to sending breaks over the serial console.   What you describe above
makes me think you aren't getting the workaround enabled.

Paul.
--

>
> http://en.wikipedia.org/wiki/Magic_SysRq_key .
>
>
>
>
> --
>
> Regards,
>  John.
>
> --
>
> o Energy-efficiency is #1 reason data centers look to expand.  -- Digital
> Realty Trust
> o Green Data Centers spending to increase 300% worldwide by 2016.  -- Pike
> Research
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> ng of society as power stations.  -- The Economist
>
>
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  reply	other threads:[~2014-02-16 15:57 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-02-14 20:42 Anyone using SysRQ key sequences on console serial port ? John Donnelly
2014-02-16 15:56 ` Paul Gortmaker [this message]
2014-02-17 19:37   ` Scott Wood
2014-02-18 19:47     ` John Donnelly
2014-02-19 18:42       ` Paul Gortmaker

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