Re: Lenovo Yoga 13 touchpad regression

["H. Peter Anvin" <hpa@zytor.com>]

On 05/06/2013 11:05 PM, Kevin Cernekee wrote:
> On Mon, May 6, 2013 at 10:25 PM, H. Peter Anvin <hpa@zytor.com> wrote:
>> Hello,
>>
>> The touchpad on Lenovo Yoga 13 seems to have broken some time between 3.4
>> and the current kernel.  The dmesg is full of spewage:
>>
>> [  256.246481] atkbd serio0: Use 'setkeycodes e03e <keycode>' to make it
>> known.
>> [  256.251473] atkbd serio0: Unknown key released (translated set 2, code
>> 0xbe on isa0060/serio0
>>
>> ... about once per second; I am wondering if the touchpad is spewing output
>> onto the keyboard channel or if there is something else wrong.
>
>  From googling around this looks like a Synaptics unit.
>
> Is it being detected by the ALPS driver?  If so, did it use the ALPS
> driver in 3.4?
>
> alps.c was changed to identify several new models, but PS/2 touchpad
> identification uses "magic knock sequences" which may be prone to
> false positives.  This is something we should watch for.
>

This is how it is detected:

[    1.843709] psmouse serio1: synaptics: Touchpad model: 1, fw: 8.1, 
id: 0x1e2b1, caps: 0xd00223/0x840300/0x123c00, board id: 1800, fw id: 
1148377
[    1.902569] input: SynPS/2 Synaptics TouchPad as 
/devices/platform/i8042/serio1/input/input3

I think this is the Synaptics driver as opposed to ALPS.

What is really bizarre is that some time today the touchpad 
spontaneously started to work.  However, after a reboot it no longer 
worked again.  This is on 3.8.11.  The keycode spewage continued, however.

	-hpa