Re: [Patch] x86, x86_64: fix cpu model for family 0x6

[Petr Vandrovec <vandrove@vc.cvut.cz>]

Siddha, Suresh B wrote:
> Andi, please pickup this patch and push to Andrew/Linus.
> 
> thanks,
> suresh
> 
> --
> According to cpuid instruction in IA32 SDM-Vol2, when computing cpu model,
> we need to consider extended model ID for family 0x6 also.
> 
> Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
> 
> --- linux-2.6.14-rc2-git7/arch/i386/kernel/cpu/common.c~	2005-09-29 17:44:12.030688920 -0700
> +++ linux-2.6.14-rc2-git7/arch/i386/kernel/cpu/common.c	2005-09-29 17:44:30.967810040 -0700
> @@ -233,10 +233,10 @@ static void __init early_cpu_detect(void
>  		cpuid(0x00000001, &tfms, &misc, &junk, &cap0);
>  		c->x86 = (tfms >> 8) & 15;
>  		c->x86_model = (tfms >> 4) & 15;
> -		if (c->x86 == 0xf) {
> +		if (c->x86 == 0xf)
>  			c->x86 += (tfms >> 20) & 0xff;
> +		if (c->x86 == 0x6 || c->x86 == 0xf)

Are you sure this is correct?  You just incremented c->x86 by extended
family, so I believe test should be

                 if (c->x86 == 0x6 || c->x86 >= 0xf)

or maybe just

                 if (c->x86 >= 0x6)

as chips with family 7..14 will either never appear, or they'll follow
existing rules (I believe all chips ever built return upper bits of tfms
zeroed, so maybe we could get rid of all these 'if' completely).
						Petr Vandrovec