Subject: Re: [PATCH] Disable i8042 checks on Intel Apple Macs
From: Bastien Nocera <hadess@hadess.net>
To: "H. Peter Anvin" <hpa@zytor.com>
Cc: Robert Hancock <hancockrwd@gmail.com>,
       Dmitry Torokhov <dmitry.torokhov@gmail.com>,
       linux-kernel <linux-kernel@vger.kernel.org>, pjones@redhat.com,
       vojtech@suse.cz
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Date: Fri, 22 Jan 2010 18:15:46 +0000
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On Fri, 2010-01-22 at 09:46 -0800, H. Peter Anvin wrote:
> On 01/21/2010 04:26 PM, Robert Hancock wrote:
> >>
> >> This is from the changelog when this was introduced:
> >>
> >> -------------------------------------------------------------------------
> >> 2005/02/25 21:21:03+01:00 vojtech
> >> input: After testing on real world hardware, it's obvious we can't trust
> >>       ACPIPnP nor PnPBIOS to properly report the existence of a keyboard
> >>       and mouse port in all cases. Some BIOSes hide the ports if no mouse
> >>       or keyboard is connected, causing trouble with eg. KVM switches.
> > 
> > If it's just that case (which isn't certain given Vojtech's report),
> > then I think it's reasonable to ignore that by default. If the BIOS
> > decided to hide the controller then our default behavior should be to
> > believe it, with the ability to override that if necessary, not the
> > other way around.
> > 
> 
> You think it's reasonable to have the keyboard not work because
> someone's KVM switch was in the wrong position when the system booted?
> Sorry, that's not how the world works.  It's sad that someone had the
> bright idea that things should work that way, but that is definitely a
> regression I wouldn't want to deal with.
> 
> The only thing that I could think of as a reasonable limit would be to
> not probe these ports if we are booted from EFI/UEFI.  That would cover
> the ia64 case, too.  However, I'm hardly confident that we wouldn't have
> the same class of problems even there.

Then I would guess that you think the manner in which I disabled the
i8042 checks in the original patch is viable/mergeable?

/Bastien, not sure who would have the last word

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