linux-kernel - Re: [rft] Kill junk from s2ram resume paths

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Message-Id: <200707311549.54863.rjw@sisk.pl>
Date:	Tue, 31 Jul 2007 15:49:54 +0200
From:	"Rafael J. Wysocki" <rjw@...k.pl>
To:	Pavel Machek <pavel@....cz>
Cc:	kernel list <linux-kernel@...r.kernel.org>,
	suspend-devel@...ts.sourceforge.net, seife@...e.de
Subject: Re: [rft] Kill junk from s2ram resume paths

Hi,

On Tuesday, 31 July 2007 15:18, Pavel Machek wrote:
> Hi!
> 
> > > This removes some stale debugging infrastructure from s2ram
> > > paths. Also, there's no need to verify_cpu on x86-64 -- cpu can't
> > > change during s2ram, and removed #if 0-ed code. Some testing would be
> > > useful, perpahs it will even fix someone's machine :-). (VGA accesses
> > > could theoretically hurt if vga is not present / if it is in some
> > > strange state).
> > > 
> > > Signed-off-by: Pavel Machek <pavel@...e.cz>
> > > 
> > > diff --git a/arch/i386/kernel/acpi/wakeup.S b/arch/i386/kernel/acpi/wakeup.S
> > > index 1415da1..9719bd6 100644
> > > --- a/arch/i386/kernel/acpi/wakeup.S
> > > +++ b/arch/i386/kernel/acpi/wakeup.S
> > > @@ -53,9 +38,6 @@ wakeup_code:
> > >  # Uncomment this to make your computer start producing ugly noise as soon
> > >  # as BIOS returns to this real-mode entry point.
> > >  #	BEEP
> > > - 	movw	$0xb800, %ax
> > > -	movw	%ax,%fs
> > > -	movw	$0x0e00 + 'L', %fs:(0x10)
> > 
> > Hmm, was this a part of that yellow "Linux" string?
> 
> Yes. But I'm afraid that may cause problems if vga is not ready.

I agree.

> > >  # Running in *copy* of this code, somewhere in low 1MB.
> > >  
> > > -	movb	$0xa1, %al	;  outb %al, $0x80
> > 
> > Well, what was this for?
> 
> Debugging leds on port 80. I still have that card somewhere
> :-). Interesting parties can reinsert it.

Ah, I see.

Hmm, can you please write about that in the chanelog more explicitly?
Or just comment it out with a "uncomment this to get ..." text?

> > > @@ -88,8 +82,6 @@ # Running in *copy* of this code, somewh
> > >  	movw	%ax,%fs
> > >  	movw	$0x0e00 + 'L', %fs:(0x10)
> > 
> > Why aren't you removing this line?
> 
> Mistake, killed.

Greetings,
Rafael


-- 
"Premature optimization is the root of all evil." - Donald Knuth
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