Ctrl-Alt-Backspace kills machine not X. ACPI?

Ctrl-Alt-Backspace kills machine not X. ACPI?

[Alex Bennee]

Hi,

I've been running into problems with my machine locking up in X but
however I have been unable to diagnose it because the Ctrl-Alt-Backspace
key sequence kills my whole machine (i.e. powers it down).

I've done some searching on google but haven't been able to find any
references except a one errata note for Mandrake that mentions disabling
the APIC which I tried and had no effect.

The Ctrl-Alt-Backspace sequence will power down my machine at any point
(BIOS Self-test, Grub, Console mode or X) but doesn't to it once Windows
is running. I have a suspicion that this is ACPI related but even with
acpi=off and apm=off flags is can still stop the box which can't be
right. Any pointers? I stand ready to provide any additional data.

-- 
Alex Bennee
Senior Hacker, Braddahead Ltd
The above is probably my personal opinion and may not be that of my
employer

Re: Ctrl-Alt-Backspace kills machine not X. ACPI?

[Dave Jones]

On Wed, Dec 04, 2002 at 12:45:45PM +0000, Alex Bennee wrote:

 > I've been running into problems with my machine locking up in X but
 > however I have been unable to diagnose it because the Ctrl-Alt-Backspace
 > key sequence kills my whole machine (i.e. powers it down).

ISTR reading something about this a while ago.
Some chipset vendor had the bright idea to make that the 'quick power
off' sequence.  I think Egbert Eich (cc'd) came up with a hack to
stop it.

		Dave

-- 
| Dave Jones.        http://www.codemonkey.org.uk
| SuSE Labs

Re: Ctrl-Alt-Backspace kills machine not X. ACPI?

[John Bradford]

>  > I've been running into problems with my machine locking up in X but
>  > however I have been unable to diagnose it because the Ctrl-Alt-Backspace
>  > key sequence kills my whole machine (i.e. powers it down).
> 
> ISTR reading something about this a while ago.

http://marc.theaimsgroup.com/?l=linux-kernel&m=103810533430878&w=2

http://marc.theaimsgroup.com/?l=linux-kernel&m=103817080229755&w=2

John.

Re: Ctrl-Alt-Backspace kills machine not X. ACPI?

[Alex Bennee]

On Wed, 2002-12-04 at 13:15, Dave Jones wrote:
> Some chipset vendor had the bright idea to make that the 'quick power
> off' sequence.  I think Egbert Eich (cc'd) came up with a hack to
> stop it.

Well I'm running a Gigabyte GA-8STXCFS which is using the
SiS645DX/SiS962L chipset. I'll certainly give the patch a spin if anyone
can throw me a pointer.

I was under the impression that once  Linux took over from the BIOS it
had complete control of the system, including the interrupt/exception
table. I am assuming some sort of interrupt or exception must be being
generated by this keypress that runs some BIOS code. Is this is the case
is that not a "Bad Thing", ACPI/APM issues aside shouldn't the kernel
only run code *it wants to*.

-- 
Alex Bennee
Senior Hacker, Braddahead Ltd
The above is probably my personal opinion and may not be that of my
employer

Re: Ctrl-Alt-Backspace kills machine not X. ACPI?

[Dave Jones]

On Wed, Dec 04, 2002 at 02:27:19PM +0000, Alex Bennee wrote:
 > I was under the impression that once  Linux took over from the BIOS it
 > had complete control of the system, including the interrupt/exception
 > table. I am assuming some sort of interrupt or exception must be being
 > generated by this keypress that runs some BIOS code.

It's likely an SMM event, which Linux doesn't even get to see.
The BIOS handles it appropriately. The chipset has a bit you can
flip to disable this 'feature', but there was a caveat iirc, something
like 'it turns itself back on every so often'.  I'll let Egbert say
more about it, as he had the relevant datasheet.

		Dave

-- 
| Dave Jones.        http://www.codemonkey.org.uk
| SuSE Labs

Re: Ctrl-Alt-Backspace kills machine not X. ACPI?

[Michael Abshoff]

Alex Bennee wrote:

>Hi,
>
>I've been running into problems with my machine locking up in X but
>however I have been unable to diagnose it because the Ctrl-Alt-Backspace
>key sequence kills my whole machine (i.e. powers it down).
>
>I've done some searching on google but haven't been able to find any
>references except a one errata note for Mandrake that mentions disabling
>the APIC which I tried and had no effect.
>
>The Ctrl-Alt-Backspace sequence will power down my machine at any point
>(BIOS Self-test, Grub, Console mode or X) but doesn't to it once Windows
>is running. I have a suspicion that this is ACPI related but even with
>acpi=off and apm=off flags is can still stop the box which can't be
>right. Any pointers? I stand ready to provide any additional data.
>
>  
>
Hello,

do you use an SIS-Board by any chance. The is a Bios-Option that powers 
down
the system. Disabeling it had no affect on my mashine, but there may be 
a Bios
update available.

I was also told that resetting the Bios via jumper might help.

Michael

-- 
Michael Abshoff - MRB - Universität Dortmund - Telefon 755-3463 (intern)

   Where do you want to RTFM today?

Re: Ctrl-Alt-Backspace kills machine not X. ACPI?

[Alex Bennee]

On Wed, 2002-12-04 at 14:47, Michael Abshoff wrote:
> do you use an SIS-Board by any chance. The is a Bios-Option that powers 
> down
> the system. Disabeling it had no affect on my mashine, but there may be 
> a Bios
> update available.

I updated the BIOS to the latest (non-Beta) flash provided by
Fujitsu/Siemens but the BIOS offers no way to dsiable power-save stuff,
just the type of suspend it does (S1 or S3).
 
> I was also told that resetting the Bios via jumper might help.

Funnily enough Gigabyte no longer carry the motherboard manual for the
GA-8STXCFS, only some of the other variants. Maybe I should take the
radical step and put LinuxBIOS on it but seeing as this is my works PC
maybe I should save that for a day when I don't have deadlines :-)

-- 
Alex Bennee
Senior Hacker, Braddahead Ltd
The above is probably my personal opinion and may not be that of my
employer

Re: Ctrl-Alt-Backspace kills machine not X. ACPI?

[XI]

Alex Bennee wrote:
> On Wed, 2002-12-04 at 12:38, XI wrote:
> 
>>Alex Bennee wrote:
>>
>>>Hi,
>>>
>>>I've been running into problems with my machine locking up in X but
>>>however I have been unable to diagnose it because the Ctrl-Alt-Backspace
>>>key sequence kills my whole machine (i.e. powers it down).
>>>
>>>I've done some searching on google but haven't been able to find any
>>>references except a one errata note for Mandrake that mentions disabling
>>>the APIC which I tried and had no effect.
>>>
>>>The Ctrl-Alt-Backspace sequence will power down my machine at any point
>>>(BIOS Self-test, Grub, Console mode or X) but doesn't to it once Windows
>>>is running. I have a suspicion that this is ACPI related but even with
>>>acpi=off and apm=off flags is can still stop the box which can't be
>>>right. Any pointers? I stand ready to provide any additional data.
>>>
>>
>>Hi,
>>I have a P.C. with short-cut CTRL+ALT+BACKSPACE to shutdown in bios. I 
>>can't find how to disable it, and I don't know if it works under windoze.
>>I think you have the same kind of stupid bios. no?
> 
> 
> The machine is a Fujitsu/Siemens based around the GA-8STXCFS motherboard
> running the latest Award BIOS 6.0PG. And yes, there is no option to
> actually disable ACPI, just change modes for S1 to S3 (shutdown vs
> suspend to RAM IIRC).
> 
> What machine have you got? Do you also experience lockups in X because
> I'm wondering if the 2 are related.
> 
> 

Hi,
I can't remember the brand and the model of the motherboard, but it is 
based on a SIS chipset. (the machine is at 1000km over). The machine 
isn't a Fujitsu, it's a "no name" machine.

I didn't remember any X lookup, I was running a mdk8.1, the machine is 
quite stable.

Xavier