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Date: Fri, 7 May 2010 23:46:59 +0100
From: Alan Cox <alan@lxorguk.ukuu.org.uk>
To: "H. Peter Anvin" <hpa@zytor.com>
Cc: Arjan van de Ven <arjan@linux.intel.com>,
       Jacob Pan <jacob.jun.pan@linux.intel.com>,
       Thomas Gleixner <tglx@linutronix.de>, Ingo Molnar <mingo@elte.hu>,
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       LKML <linux-kernel@vger.kernel.org>,
       Jacob Pan <jacob.jun.pan@intel.com>,
       Linus Torvalds <torvalds@linux-foundation.org>,
       Arjan van de Ven <arjan.van.de.ven@intel.com>
Subject: Re: RFD: Should we remove the HLT check?  (was Re: [PATCH 1/8] x86:
 avoid check hlt if no timer interrupts)
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On Fri, 07 May 2010 15:27:34 -0700
"H. Peter Anvin" <hpa@zytor.com> wrote:

> On 05/07/2010 03:24 PM, Alan Cox wrote:
> >> I'd be cool skipping it for family 5 or newer.  I'm just wondering if we
> >> should kill it completely -- IIRC it was only a handful of 386/486
> >> systems which had problems, usually due to marginal power supplies which
> >> couldn't handle the noise of a variable load (DOS not having any power
> >> management would run at a reliable 100% load) -- that's not exactly the
> >> type of systems which would have survived to modern day.
> > 
> > Also SMM and hardware bugs on some platforms - Cyrix MediaGX 5510 for
> > example where a hlt at the wrong moment during ATA transfers hung the box
> > until power cycle. But all old old stuff.
> 
> I think family < 5 seems a reasonable cutoff.
> 
> Note that the ATA transfer bug you describe above would not be caught by
> the existing check.

MediaGX5510 would I'm pretty certain be 486 reporting anyway