MSR_SPE - being turned off...

[Kumar Gala]

On May 5, 2009, at 7:56 AM, Morrison, Tom wrote:

> Hi Kumar/Michael...
>
> Sorry, I really didn't explain myself very well...
>
> The Problem (answer to Michael):
> ================================
> We started using a new compiler that upon -O2 optimization - added
> heavy SPE related instructions into our applications (where the older
> compiler might not use as many). Once this was done, we started
> experiencing problems with data being 'shifted' and/or corrupted
> throughout the applications which didn't immediately cause problems,
> but either scribbled on someone else's memory and/or bad results...
> We knew where one of the offending scribbles started (by the shifting
> by 1 byte of a structure) and found by comparing binaries with 'older'
> compiler vs. this one that the only major difference was the 'density'
> of the SPE instructions...
>
> As to your question, Kumar:
> ===========================
> Naively, I explicitly enabled the SPE in a BSP 'early_init' program
> (as well as enabling Machine Checks) - which is what I meant by
> Enabling SPE...

Are you setting MSR_SPE in your own board code?  If so stop doing so.   
There isn't any need or reason to be doing that.  MSR_SPE will get set  
when an application starts using SPE code and the kernel will manage  
it properly.

- k