Strange kernel reboot (oops?)

Strange kernel reboot (oops?)

[Ezequiel García]

Hi,

While running an embedded linux platform (sh4) with an old linux kernel (2.6.23), I'm trying to debug a very strange behavior (at least strange to me). The box is running aparently fine, and out of nothing it is rebooting.

There is no "Caught signal ..." message, no kernel oops message, just a plain cpu reboot. After the reboot, the linux kernel boots but somewhere before running the user application it panics. 

The kernel panic message seems useless, because the system is booting. When power is unplugged and re-plugged, the system starts normally.

Has anyone seeing this kind of behavior before? 

Thanks,
Ezequiel.

Strange kernel reboot (oops?)

[Mulyadi Santosa]

Hi Ezequiel...

2011/12/26 Ezequiel Garc?a <elezegarcia@yahoo.com.ar>:
> Hi,
>
> While running an embedded linux platform (sh4) with an old linux kernel (2.6.23), I'm trying to debug a very strange behavior (at least strange to me). The box is running aparently fine, and out of nothing it is rebooting.
>
> There is no "Caught signal ..." message, no kernel oops message, just a plain cpu reboot. After the reboot, the linux kernel boots but somewhere before running the user application it panics.

I know nothing about sh4 platform, but everytime I heard troubles like
yours, RAM problem rings the bell inside my head first. So maybe you
can check that first...using something like memtest if it is x86...

-- 
regards,

Mulyadi Santosa
Freelance Linux trainer and consultant

blog: the-hydra.blogspot.com
training: mulyaditraining.blogspot.com

Strange kernel reboot (oops?)

[Mulyadi Santosa]

Hi :)

2011/12/27 Ezequiel Garc?a <elezegarcia@yahoo.com.ar>:
> We've solved the bug that originated this in first place,
> so... never mind :) It was strange indeed...
>
> Thanks anyway for you help.
>
> Embedded-land is a strange world to live in.

Wow nice :) Anyway, mind to share a bit, what was the solution? if it
is not top secret :)


-- 
regards,

Mulyadi Santosa
Freelance Linux trainer and consultant

blog: the-hydra.blogspot.com
training: mulyaditraining.blogspot.com

Strange kernel reboot (oops?)

[Ezequiel García]

--- El mar 27-dic-11, Mulyadi Santosa <mulyadi.santosa@gmail.com> escribi?:

> De: Mulyadi Santosa <mulyadi.santosa@gmail.com>
> Asunto: Re: Strange kernel reboot (oops?)
> Para: "Ezequiel Garc?a" <elezegarcia@yahoo.com.ar>
> Cc: "kernelnewbies" <Kernelnewbies@kernelnewbies.org>
> Fecha: martes, 27 de diciembre de 2011, 9:15
> Hi :)
> 
> 2011/12/27 Ezequiel Garc?a <elezegarcia@yahoo.com.ar>:
> > We've solved the bug that originated this in first
> place,
> > so... never mind :) It was strange indeed...
> >
> > Thanks anyway for you help.
> >
> > Embedded-land is a strange world to live in.
> 
> Wow nice :) Anyway, mind to share a bit, what was the
> solution? if it
> is not top secret :)

Nah, it's not a secret.
We have a device with hdmi out, the sudden reboot bug was triggered somewhere in the hdmi out digital resolution change (1080, 720, etc)... 
so we changed the way the digital resolution is changed and the bug 
magically disapparead :)

I am not very familiar with the inners of this particular SoC chip so I can't really imagine how can the system reboot in such a way. 

Thanks,
Ezequiel.

Strange kernel reboot (oops?)

[Mulyadi Santosa]

Hi :)

2011/12/27 Ezequiel Garc?a <elezegarcia@yahoo.com.ar>:
> Nah, it's not a secret.
> We have a device with hdmi out, the sudden reboot bug was triggered somewhere in the hdmi out digital resolution change (1080, 720, etc)...
> so we changed the way the digital resolution is changed and the bug
> magically disapparead :)
>
> I am not very familiar with the inners of this particular SoC chip so I can't really imagine how can the system reboot in such a way.

Hm, i see..... this is the first time I heard a system could reboot
due to resolution change. But....always nice to know.

Thanks for sharing and good luck with the project :)

-- 
regards,

Mulyadi Santosa
Freelance Linux trainer and consultant

blog: the-hydra.blogspot.com
training: mulyaditraining.blogspot.com