linux-kernel - Re: [PATCH] Display Intel Dynamic Acceleration feature in /proc/cpuinfo

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Message-ID: <46560E4F.2080009@zytor.com>
Date:	Thu, 24 May 2007 15:14:39 -0700
From:	"H. Peter Anvin" <hpa@...or.com>
To:	Andrew Morton <akpm@...ux-foundation.org>
CC:	Venki Pallipadi <venkatesh.pallipadi@...el.com>,
	Dave Jones <davej@...hat.com>, Len Brown <len.brown@...el.com>,
	linux-kernel <linux-kernel@...r.kernel.org>,
	Andi Kleen <ak@...e.de>
Subject: Re: [PATCH] Display Intel Dynamic Acceleration feature in /proc/cpuinfo

Andrew Morton wrote:
> 
> I'm not sure I can be bothered repairing all that at present.  I think I'll
> go and hide until it becomes somebody else's problem.
> 

I'll fix it.

> <looks at hpa's tree>
> 
> @@ -23,13 +23,14 @@ static int show_cpuinfo(struct seq_file 
>                 "fpu", "vme", "de", "pse", "tsc", "msr", "pae", "mce",
>                 "cx8", "apic", NULL, "sep", "mtrr", "pge", "mca", "cmov",
>                 "pat", "pse36", "pn", "clflush", NULL, "dts", "acpi", "mmx",
> -               "fxsr", "sse", "sse2", "ss", "ht", "tm", "ia64", "pbe",
> +               "fxsr", "sse", "sse2", "ss", "ht", "tm", "ia64", NULL,
> 
> <wonders where pbe went to>

pbe collides with abuse by at least two vendors (AMD and
Cyrix/Centaur/VIA) of this bit for 3DNow.  I don't know if that applies
only to the chips that don't support extended CPUID levels, but I'm
fairly sure that we don't handle that correctly in the vendor-specific
handlers.

I guess for now we can just unconditionally disable that bit in those
vendor routines, with a note saying that if there are such chips
supporting PBE then more sophisticated logic needs to be implemented.

	-hpa
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