Re: AMD errata 169

On Fri, 26 Jun 2009 12:37:27 +0100
Ian J Hart <ianjhart_at_ntlworld.com> mentioned:

> I know I asked this before but I figure the long post may have put  
> some people off.
> 
> #169
> http://www.amd.com/us-en/assets/content_type/white_papers_and_tech_docs/25759.pdf
> 
> I'd like to eliminate this as a cause of my problem
> 
> It appears I can read the value.
> 
> #kldload cpuctl
> #cpucontrol -m 0xc001001f /dev/cpuctl0
> MSR 0xc001001f: 0x00400000 0x00100008
> 
> #cpucontrol -m 0xc001001f=0x0040000000100008 /dev/cpuctl0
> 
> Causes an nfe0 watchdog timeout and a powerdown failed, so that's  
> clearly a dumb thing to do.
> 
> Would I be better off asking somewhere else?
> 

Hi, Ian.

Currently, it is not possible to atomically set the value of specific bits
of MSR registers with cpuctl.  I suspect this might be a problem, as 
the value of this MSR register could change between calls. Do you
run stable or current?

BTW, is there description of this NB_CFG MSR register somewhere on the
net?  I think that some bits of this register could have specific meaning
and it is not safe to write them.

-- 
Stanislav Sedov
ST4096-RIPE