Re: boot_cpu_data.x86_vendor corruption on dual AMD

[Maciej W. Rozycki]

On Wed, 13 Mar 2002, Mikael Pettersson wrote:

> I'm involved with debugging a driver problem which only appears
> on dual AMD systems. When the driver's module_init() is called,
> boot_cpu_data.x86_vendor is 0 (Intel) instead of 2 (AMD), causing
> incorrect code to be selected and eventually an oops.
> 
> We've so far traced it to the call to smp_init() in init/main.c.
> Before this call, boot_cpu_data.x86_vendor is 2 (correct), but
> after the call, the field is 0.

 Code in arch/i386/kernel/head.S (look below checkCPUtype) clears
boot_cpu_data.x86_vendor and it does not get reconstructed after secondary
bootstraps.  A common x86_vendor does not make sense anyway, at least in
principle (the whole cpu_data handling needs a rework but I have no time
to continue what I started last year and nobody else seems to work on it
either).  Wouldn't current_cpu_data.x86_vendor suffice?  That will work
for sure. 

-- 
+  Maciej W. Rozycki, Technical University of Gdansk, Poland   +
+--------------------------------------------------------------+
+        e-mail: [e-mail], PGP key available        +