ac100 team mailing list archive

[Marc Dietrich <marvin24@xxxxxx>]

Hi Gordan,

Am Freitag 19 August 2011, 11:18:31 schrieb Gordan Bobic:
>  As some of you may have already heard on the IRC channel, I had my
>  AC100 suddenly become very unstable under load. When doing big compile
> [...]
>  My gut feeling at the moment is that the RAM could be over-timed so I'm
>  going to try modifying the kernel code to relax the RAM timings by a
>  notch.

we are not touching RAM timings so far on kernel 2.6.38. It may be possible that 
the original kernels does so. 
 
>  The only competing idea is that Tegra2 comes pre-overclocked past the
>  stable limits for 100% load for prolonged periods. This wouldn't
>  surprise me either (Nvidia chips have proven unreliable in the past even
>  at their default clock speeds, both the motherboard chipsets and GPUs),
>  but I would like to think that Toshiba would have done some due
>  dilligence testing of their product. For comparison, my SheevaPlug is
>  compiling 24/7 for weeks at a time and has never errored out.

It could also be related to power supply. What we do is modifing the voltage 
supplies for serveral power sources. I had the feeling, that Toshiba 
undervoltaged some CPU supplies in order to save energy (compared to other 
boards). So I increased SM1 from 1V to 1.2V which may have been wrong. 

It would be nice if you could test a .32 based kernel and see if it also happens 
there. Also you could try your new model.

Finially, it could also be possible that this is a design bug, which may be hard 
to solve for us.

Marc