linux-kernel - Re: [PATCH] x86: provide a DMI based port 0x80 I/O delay override

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Message-ID: <20071230210007.GA3136@elte.hu>
Date:	Sun, 30 Dec 2007 22:00:07 +0100
From:	Ingo Molnar <mingo@...e.hu>
To:	"H. Peter Anvin" <hpa@...or.com>
Cc:	Bodo Eggert <7eggert@....de>, Alan Cox <alan@...rguk.ukuu.org.uk>,
	Linus Torvalds <torvalds@...ux-foundation.org>,
	Rene Herman <rene.herman@...access.nl>, dpreed@...d.com,
	Islam Amer <pharon@...il.com>, Pavel Machek <pavel@....cz>,
	Ingo Molnar <mingo@...hat.com>,
	Andi Kleen <andi@...stfloor.org>,
	Thomas Gleixner <tglx@...utronix.de>,
	Linux Kernel <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH] x86: provide a DMI based port 0x80 I/O delay override


* H. Peter Anvin <hpa@...or.com> wrote:

> Ingo Molnar wrote:
>> * Bodo Eggert <7eggert@....de> wrote:
>>
>>> BTW: The error function in linux-2.6.23/arch/i386/boot/compressed/misc.c 
>>> uses while(1) without cpu_relax() in order to halt the machine. Is this 
>>> fixed? Should it be fixed?
>>
>> this is early bootup so there's no need to be "nice" to other cores or 
>> sockets - none of them are really running.
>>
>
> It probably should actually HLT, to avoid sucking power, and stressing 
> the thermal system.  We're dead at this point, and the early 486's 
> which had problems with HLT will lock up - we don't care.

ok. Like the patch below?

	Ingo

---------->
Subject: x86: hlt on early crash
From: Ingo Molnar <mingo@...e.hu>

H. Peter Anvin <hpa@...or.com> wrote:

> It probably should actually HLT, to avoid sucking power, and stressing
> the thermal system.  We're dead at this point, and the early 486's
> which had problems with HLT will lock up - we don't care.

Signed-off-by: Ingo Molnar <mingo@...e.hu>
---
 arch/x86/boot/compressed/misc_32.c |    2 +-
 arch/x86/boot/compressed/misc_64.c |    2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

Index: linux-x86.q/arch/x86/boot/compressed/misc_32.c
===================================================================
--- linux-x86.q.orig/arch/x86/boot/compressed/misc_32.c
+++ linux-x86.q/arch/x86/boot/compressed/misc_32.c
@@ -339,7 +339,7 @@ static void error(char *x)
 	putstr(x);
 	putstr("\n\n -- System halted");
 
-	while(1);	/* Halt */
+	asm("cli; hlt");	/* Halt */
 }
 
 asmlinkage void decompress_kernel(void *rmode, unsigned long end,
Index: linux-x86.q/arch/x86/boot/compressed/misc_64.c
===================================================================
--- linux-x86.q.orig/arch/x86/boot/compressed/misc_64.c
+++ linux-x86.q/arch/x86/boot/compressed/misc_64.c
@@ -338,7 +338,7 @@ static void error(char *x)
 	putstr(x);
 	putstr("\n\n -- System halted");
 
-	while(1);	/* Halt */
+	asm("cli; hlt");	/* Halt */
 }
 
 asmlinkage void decompress_kernel(void *rmode, unsigned long heap,
--
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