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Date: Wed, 15 May 2002 08:36:45 -0500
From: Tommy Reynolds <reynolds@redhat.com>
To: "Bloch, Jack" <Jack.Bloch@icn.siemens.com>
Cc: linux-kernel@vger.kernel.org
Subject: Re: Device driver question
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Uttered "Bloch, Jack" <Jack.Bloch@icn.siemens.com>, spoke thus:

> I have a specific case where our HW can generate a
>  special interrupt. In this case I simply want the ISR to halt the system
>  (i.e. take the same action as if I typed halt from the command line). How
>  can I from within my device driver cause a halt? Please CC me specifically
>  on any replies.

Check out the code for "sys_reboot" in "kernel/sys.c" for ideas on how to do
this.  I don't think you can invoke "sys_reboot" from inside an interrupt
handler, but you could probably do the same thing by calling the service
routines "sys_reboot" does.

If that doesn't shut your machine down gracefully, then you might resort to
"call_usermodehelper" in "kernel/kmod.c" to run "/sbin/shutdown -h now".  You
can't invoke "call_usermodehelper" from an interrupt top half, but it should
work find from a tasklett.