Message-ID: <4B58FD48.9020209@gmail.com>
Date:	Thu, 21 Jan 2010 17:20:08 -0800
From:	"Justin P. Mattock" <justinmattock@...il.com>
To:	Robert Hancock <hancockrwd@...il.com>
CC:	Dmitry Torokhov <dmitry.torokhov@...il.com>,
	Bastien Nocera <hadess@...ess.net>,
	linux-kernel <linux-kernel@...r.kernel.org>, pjones@...hat.com
Subject: Re: [PATCH] Disable i8042 checks on Intel Apple Macs

On 01/21/10 16:29, Robert Hancock wrote:
> On Thu, Jan 21, 2010 at 3:49 PM, Justin P. Mattock
> <justinmattock@...il.com>  wrote:
>> On 01/21/10 13:39, Robert Hancock wrote:
>>>
>>> On Thu, Jan 21, 2010 at 12:55 PM, Dmitry Torokhov
>>> <dmitry.torokhov@...il.com>    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@...ess.net>
>>>>>
>>>>> 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.
>
> Can you (and probably Bastien or whoever had the problematic machine)
> check the output of:
>
> cat /sys/bus/pnp/devices/*/id
>
> and see if any of these are present?
>
> PNP0303
> PNP030b
> FJC6000
> FJC6001
> PNP0f03
> PNP0f0b
> PNP0f0e
> PNP0f12
> PNP0f13
> PNP0f19
> PNP0f1c
> SYN0801
>


both macbook pro, and iMac9,1
have:
PNP0a08
PNP0a03

Justin P. Mattock
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