Re: [PATCH] Disable i8042 checks on Intel Apple Macs

[Justin P. Mattock]

On 01/21/10 13:39, Robert Hancock wrote:
> On Thu, Jan 21, 2010 at 12:55 PM, Dmitry Torokhov
> <dmitry.torokhov@xxxxxxxxx>  wrote:
> > On Wed, Jan 20, 2010 at 06:41:56PM -0600, Robert Hancock wrote:
> > > On 01/20/2010 12:23 PM, Bastien Nocera wrote:
> > > > As those computers never had any i8042 controllers, and the
> > > > current lookup code could potentially lock up/hang/wait for
> > > > timeout for long periods of time.
> > > >
> > > > Fixes intermittent hangs on boot on a MacbookAir1,1
> > > >
> > > > Signed-off-by: Bastien Nocera<hadess@xxxxxxxxxx>
> > >
> > > I assume this is happening because of this code in
> > > drivers/input/serio/i8042-x86ia64io.h:
> > >
> > >          if (!i8042_pnp_kbd_devices&&  !i8042_pnp_aux_devices) {
> > >                  i8042_pnp_exit();
> > > #if defined(__ia64__)
> > >                  return -ENODEV;
> > > #else
> > >                  printk(KERN_INFO "PNP: No PS/2 controller found.
> > > Probing ports directly.\n");
> > >                  return 0;
> > > #endif
> > >
> > > In other words, on x86, if PNP and/or ACPI don't indicate any PS/2
> > > controller exists, we randomly bang on the ports in the expectation
> > > they'll be there anyway. This seems rather misguided.
> >
> > Basically, we do not trust BIOS writers on x86 ;) In the past there were
> > occasions when they forgot to mention presence of KBD/AUX in DSDT and
> > elsewhere which lead to non-functional keyboard/mouse.
>
> Are we certain about that? Any pointers to reports?
>
> > > It would seem
> > > like a better idea to fix this rather than adding yet another DMI
> > > list (especially since there likely are, or will be, machines
> > > without i8042 other than Macs).
> >
> > If they are not Macs that mean they are tested with windows and thus
> > expect probes in i8042 port region so no harm done. In a few years if
> > everyone uses USB only we could add a year threshold to trust ACPI/PNP
> > data.
>
> Macs will be tested with Windows too, so obviously it manages to avoid
> this problem somehow, and I very much doubt it has an Apple-specific
> check..
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I've an iMac, and a macbook over here,
if you guys need me to test out a patch for this let me know.

Justin P. Mattock
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